Publications of Brian Hare

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@article{fds369844,
   Author = {Salomons, H and Smith, KCM and Callahan-Beckel, M and Callahan, M and Levy, K and Kennedy, BS and Bray, EE and Gnanadesikan, GE and Horschler,
             DJ and Gruen, M and Tan, J and White, P and vonHoldt, BM and MacLean, EL and Hare, B},
   Title = {Response to Hansen Wheat et al.: Additional analysis further
             supports the early emergence of cooperative communication in
             dogs compared to wolves raised with more human
             exposure.},
   Journal = {Learning & behavior},
   Volume = {51},
   Number = {2},
   Pages = {131-134},
   Year = {2023},
   Month = {June},
   Abstract = {Here, we address Hansen Wheat et al.'s commentary in this
             journal in response to Salomons et al. Current Biology,
             31(14), 3137-3144.E11, (2021). We conduct additional
             analyses in response to Hansen Wheat et al.'s two main
             questions. First, we examine the claim that it was the move
             to a human home environment which enabled the dog puppies to
             outperform the wolf puppies in gesture comprehension tasks.
             We show that the youngest dog puppies who had not yet been
             individually placed in raisers' homes were still highly
             skilled, and outperformed similar-aged wolf puppies who had
             higher levels of human interaction. Second, we address the
             claim that willingness to approach a stranger can explain
             the difference between dog and wolf pups' ability to succeed
             in gesture comprehension tasks. We explain the various
             controls in the original study that render this explanation
             insufficient, and demonstrate via model comparison that the
             covariance of species and temperament also make this parsing
             impossible. Overall, our additional analyses and
             considerations support the domestication hypothesis as laid
             out by Salomons et al. Current Biology, 31(14),
             3137-3144.E11, (2021).},
   Doi = {10.3758/s13420-023-00576-2},
   Key = {fds369844}
}

@article{fds363720,
   Author = {Zhou, W and Hare, B},
   Title = {The Early Expression of Blatant Dehumanization in Children
             and Its Association with Outgroup Negativity.},
   Journal = {Human nature (Hawthorne, N.Y.)},
   Volume = {33},
   Number = {2},
   Pages = {196-214},
   Year = {2022},
   Month = {June},
   Abstract = {Dehumanization is observed in adults across cultures and is
             thought to motivate human violence. The age of its first
             expression remains largely untested. This research
             demonstrates that diverse representations of humanness,
             including a novel one, readily elicit blatant dehumanization
             in adults (N = 482) and children (aged 5-12;
             N = 150). Dehumanizing responses in both age groups are
             associated with support for outgroup inferiority. Similar to
             the link previously observed in adults, dehumanization by
             children is associated with a willingness to punish outgroup
             transgressors. These findings suggest that exposure to
             cultural norms throughout adolescence and adulthood are not
             required for the development of outgroup
             dehumanization.},
   Doi = {10.1007/s12110-022-09427-x},
   Key = {fds363720}
}

@article{fds359024,
   Author = {Rimbach, R and Amireh, A and Allen, A and Hare, B and Guarino, E and Kaufman, C and Salomons, H and Pontzer, H},
   Title = {Total energy expenditure of bottlenose dolphins (Tursiops
             truncatus) of different ages.},
   Journal = {The Journal of experimental biology},
   Year = {2021},
   Month = {July},
   Abstract = {Marine mammals are thought to have an energetically
             expensive lifestyle because endothermy is costly in marine
             environments. However, measurements of total energy
             expenditure (TEE; kcal/day) are available only for a limited
             number of marine mammals, because large body size and
             inaccessible habitats make TEE measurements expensive and
             difficult for many taxa. We measured TEE in 10 adult common
             bottlenose dolphins (Tursiops truncatus) living in natural
             seawater lagoons at two facilities (Dolphin Research Center
             and Dolphin Quest) using the doubly labeled water method. We
             assessed the relative effects of body mass, age, and
             physical activity on TEE. We also examined whether TEE of
             bottlenose dolphins, and more generally marine mammals,
             differs from that expected for their body mass compared to
             other eutherian mammals, using phylogenetic least squares
             (PGLS) regressions. There were no differences in body mass
             or TEE (unadjusted TEE and TEE adjusted for fat free mass
             (FFM)) between dolphins from both facilities. Our results
             show that Adjusted TEE decreased and fat mass (FM) increased
             with age. Different measures of activity were not related to
             age, body fat or Adjusted TEE. Both PGLS and the
             non-phylogenetic linear regression indicate that marine
             mammals have an elevated TEE compared to terrestrial
             mammals. However, bottlenose dolphins expended 17.1% less
             energy than other marine mammals of similar body mass. The
             two oldest dolphins (>40 years) showed a lower TEE, similar
             to the decline in TEE seen in older humans. To our
             knowledge, this is the first study to show an age-related
             metabolic decline in a large non-human mammal.},
   Doi = {10.1242/jeb.242218},
   Key = {fds359024}
}

@article{fds358337,
   Author = {Salomons, H and Smith, KCM and Callahan-Beckel, M and Callahan, M and Levy, K and Kennedy, BS and Bray, EE and Gnanadesikan, GE and Horschler,
             DJ and Gruen, M and Tan, J and White, P and vonHoldt, BM and MacLean, EL and Hare, B},
   Title = {Cooperative Communication with Humans Evolved to Emerge
             Early in Domestic Dogs.},
   Journal = {Current biology : CB},
   Volume = {31},
   Number = {14},
   Pages = {3137-3144.e11},
   Year = {2021},
   Month = {July},
   Abstract = {Although we know that dogs evolved from wolves, it remains
             unclear how domestication affected dog cognition. One
             hypothesis suggests dog domestication altered social
             maturation by a process of selecting for an attraction to
             humans.<sup>1-3</sup> Under this account, dogs became more
             flexible in using inherited skills to cooperatively
             communicate with a new social partner that was previously
             feared and expressed these unusual social skills early in
             development.<sup>4-6</sup> Here, we comparedog (n = 44) and
             wolf (n = 37) puppies, 5-18 weeks old, on a battery of
             temperament and cognition tasks. We find that dog puppies
             are more attracted to humans, read human gestures more
             skillfully, and make more eye contact with humans than wolf
             puppies. The two species are similarly attracted to familiar
             objects and perform similarly on non-social measures of
             memory and inhibitory control. These results are consistent
             with the idea that domestication enhanced the
             cooperative-communicative abilities of dogs as selection for
             attraction to humans altered social maturation.},
   Doi = {10.1016/j.cub.2021.06.051},
   Key = {fds358337}
}

@article{fds356121,
   Author = {Pontzer, H and Brown, MH and Wood, BM and Raichlen, DA and Mabulla, AZP and Harris, JA and Dunsworth, H and Hare, B and Walker, K and Luke, A and Dugas, LR and Schoeller, D and Plange-Rhule, J and Bovet, P and Forrester, TE and Thompson, ME and Shumaker, RW and Rothman, JM and Vogel, E and Sulistyo, F and Alavi, S and Prasetyo, D and Urlacher, SS and Ross, SR},
   Title = {Evolution of water conservation in humans.},
   Journal = {Current biology : CB},
   Volume = {31},
   Number = {8},
   Pages = {1804-1810.e5},
   Year = {2021},
   Month = {April},
   Abstract = {To sustain life, humans and other terrestrial animals must
             maintain a tight balance of water gain and water loss each
             day.<sup>1-3</sup> However, the evolution of human water
             balance physiology is poorly understood due to the absence
             of comparative measures from other hominoids. While humans
             drink daily to maintain water balance, rainforest-living
             great apes typically obtain adequate water from their food
             and can go days or weeks without drinking<sup>4-6</sup>.
             Here, we compare isotope-depletion measures of water
             turnover (L/d) in zoo- and rainforest-sanctuary-housed apes
             (chimpanzees, bonobos, gorillas, and orangutans) with 5
             diverse human populations, including a hunter-gatherer
             community in a semi-arid savannah. Across the entire sample,
             water turnover was strongly related to total energy
             expenditure (TEE, kcal/d), physical activity, climate
             (ambient temperature and humidity), and fat free mass. In
             analyses controlling for those factors, water turnover was
             30% to 50% lower in humans than in other apes despite
             humans' greater sweating capacity. Water turnover in zoo and
             sanctuary apes was similar to estimated turnover in wild
             populations, as was the ratio of water intake to dietary
             energy intake (∼2.8 mL/kcal). However, zoo and sanctuary
             apes ingested a greater ratio of water to dry matter of
             food, which might contribute to digestive problems in
             captivity. Compared to apes, humans appear to target a lower
             ratio of water/energy intake (∼1.5 mL/kcal). Water stress
             due to changes in climate, diet, and behavior apparently led
             to previously unknown water conservation adaptations in
             hominin physiology.},
   Doi = {10.1016/j.cub.2021.02.045},
   Key = {fds356121}
}

@article{fds353051,
   Author = {Bray, EE and Gruen, ME and Gnanadesikan, GE and Horschler, DJ and Levy,
             KM and Kennedy, BS and Hare, BA and MacLean, EL},
   Title = {Dog cognitive development: a longitudinal study across the
             first 2 years of life.},
   Journal = {Animal cognition},
   Volume = {24},
   Number = {2},
   Pages = {311-328},
   Year = {2021},
   Month = {March},
   Abstract = {While our understanding of adult dog cognition has grown
             considerably over the past 20 years, relatively little is
             known about the ontogeny of dog cognition. To assess the
             development and longitudinal stability of cognitive traits
             in dogs, we administered a battery of tasks to 160 candidate
             assistance dogs at 2 timepoints. The tasks were designed to
             measure diverse aspects of cognition, ranging from executive
             function (e.g., inhibitory control, reversal learning,
             memory) to sensory discrimination (e.g., vision, audition,
             olfaction) to social interaction with humans. Subjects first
             participated as 8-10-week-old puppies, and then were
             retested on the same tasks at ~ 21 months of age. With few
             exceptions, task performance improved with age, with the
             largest effects observed for measures of executive function
             and social gaze. Results also indicated that individual
             differences were both early emerging and enduring; for
             example, social attention to humans, use of human
             communicative signals, independent persistence at a problem,
             odor discrimination, and inhibitory control all exhibited
             moderate levels of rank-order stability between the two
             timepoints. Using multiple regression, we found that young
             adult performance on many cognitive tasks could be predicted
             from a set of cognitive measures collected in early
             development. Our findings contribute to knowledge about
             changes in dog cognition across early development as well as
             the origins and developmental stability of individual
             differences.},
   Doi = {10.1007/s10071-020-01443-7},
   Key = {fds353051}
}

@article{fds355599,
   Author = {Hare, B and Ferrans, M},
   Title = {Is cognition the secret to working dog success?},
   Journal = {Animal cognition},
   Volume = {24},
   Number = {2},
   Pages = {231-237},
   Year = {2021},
   Month = {March},
   Abstract = {Dogs' special relationship with humans not only makes them
             ubiquitous in our lives, but working dogs specifically
             perform essential functions for us such as sniffing out
             bombs and pulling wheelchairs for the disabled. To enhance
             the performance of working dogs, it is essential to
             understand the cognitive skills that underlie and lead to
             their success. This review details recent work in the field
             of canine cognition, including how dogs have evolved
             socio-cognitive skills that mimic or, in some cases, rival
             even our closest primate relatives. We review how these
             findings have laid the foundation for new studies that hope
             to help enhance working dog programs. This includes work
             that has begun to reveal the development and stability of
             the most important traits for service work. Discoveries like
             these suggest the possibility of translating what we have
             learned to improve breeding, selection, and training for
             these jobs. The latest research we review here shows promise
             in contributing to the production of better dogs and,
             consequently, more help for people.},
   Doi = {10.1007/s10071-021-01491-7},
   Key = {fds355599}
}

@article{fds353832,
   Author = {Bowie, A and Walker, K and Bunnell, G and Morel, D and Minesi, F and Belais, R and Hare, B},
   Title = {Assessing conservation attitudes and behaviors of Congolese
             children neighboring the world's first bonobo (Pan paniscus)
             release site.},
   Journal = {American journal of primatology},
   Volume = {83},
   Number = {1},
   Pages = {e23217},
   Year = {2021},
   Month = {January},
   Abstract = {Poaching and habitat destruction in the Congo Basin threaten
             African great apes including the bonobo (Pan paniscus),
             chimpanzees (Pan troglodytes), and gorillas (Gorilla spp.)
             with extinction. One way to combat extinction is to
             reintroduce rescued and rehabilitated apes and repopulate
             native habitats. Reintroduction programs are only successful
             if they are supported by local populations. Ekolo ya Bonobo,
             located in Equateur province of the Democratic Republic of
             Congo (DRC), is the world's only reintroduction site for
             rehabilitated bonobos. Here we assess whether children, of
             the Ilonga-Pôo, living adjacent to Ekolo ya Bonobo
             demonstrate more pro-ape conservation attitudes than
             children living in, Kinshasa, the capital city. We examined
             children's attitudes toward great apes because children are
             typically the focus of conservation education programs. We
             used the Great Ape Attitude Questionnaire to test the
             Contact Hypothesis, which posits that proximity to great ape
             habitat influences pro-conservation attitudes toward great
             apes. Ilonga-Pôo children who live in closer contact with
             wild bonobos felt greater responsibility to protect great
             apes compared to those in Kinshasa who live outside the
             natural habitat of great apes. These results suggest that
             among participants in the DRC, spatial proximity to a
             species fosters a greater sense of responsibility to protect
             and conserve. These results have implications for the
             successful implementation of great ape reintroduction
             programs in the Congo Basin. The data analyzed in this study
             were collected in 2010 and therefore provide a baseline for
             longitudinal study of this reintroduction
             site.},
   Doi = {10.1002/ajp.23217},
   Key = {fds353832}
}

@article{fds353050,
   Author = {Gnanadesikan, GE and Hare, B and Snyder-Mackler, N and Call, J and Kaminski, J and Miklósi, Á and MacLean, EL},
   Title = {Breed Differences in Dog Cognition Associated with
             Brain-Expressed Genes and Neurological Functions.},
   Journal = {Integrative and comparative biology},
   Volume = {60},
   Number = {4},
   Pages = {976-990},
   Year = {2020},
   Month = {October},
   Abstract = {Given their remarkable phenotypic diversity, dogs present a
             unique opportunity for investigating the genetic bases of
             cognitive and behavioral traits. Our previous work
             demonstrated that genetic relatedness among breeds accounts
             for a substantial portion of variation in dog cognition.
             Here, we investigated the genetic architecture of breed
             differences in cognition, seeking to identify genes that
             contribute to variation in cognitive phenotypes. To do so,
             we combined cognitive data from the citizen science project
             Dognition.com with published breed-average genetic
             polymorphism data, resulting in a dataset of 1654
             individuals with cognitive phenotypes representing 49
             breeds. We conducted a breed-average genome-wide association
             study to identify specific polymorphisms associated with
             breed differences in inhibitory control, communication,
             memory, and physical reasoning. We found five single
             nucleotide polymorphisms (SNPs) that reached genome-wide
             significance after Bonferroni correction, located in EML1,
             OR52E2, HS3ST5, a U6 spliceosomal RNA, and a long noncoding
             RNA. When we combined results across multiple SNPs within
             the same gene, we identified 188 genes implicated in breed
             differences in cognition. This gene set included more genes
             than expected by chance that were (1) differentially
             expressed in brain tissue and (2) involved in nervous system
             functions including peripheral nervous system development,
             Wnt signaling, presynapse assembly, and synaptic vesicle
             exocytosis. These results advance our understanding of the
             genetic underpinnings of complex cognitive phenotypes and
             identify specific genetic variants for further
             research.},
   Doi = {10.1093/icb/icaa112},
   Key = {fds353050}
}

@article{fds350126,
   Author = {Gnanadesikan, GE and Hare, B and Snyder-Mackler, N and MacLean,
             EL},
   Title = {Estimating the heritability of cognitive traits across dog
             breeds reveals highly heritable inhibitory control and
             communication factors.},
   Journal = {Animal cognition},
   Volume = {23},
   Number = {5},
   Pages = {953-964},
   Year = {2020},
   Month = {September},
   Abstract = {Trait heritability is necessary for evolution by both
             natural and artificial selection, yet we know little about
             the heritability of cognitive traits. Domestic dogs are a
             valuable study system for questions regarding the evolution
             of phenotypic diversity due to their extraordinary
             intraspecific variation. While previous studies have
             investigated morphological and behavioral variation across
             dog breeds, few studies have systematically assessed breed
             differences in cognition. We integrated data from
             Dognition.com-a citizen science project on dog
             cognition-with breed-averaged genetic data from published
             sources to estimate the among-breed heritability of
             cognitive traits using mixed models. The resulting dataset
             included 11 cognitive measures for 1508 adult dogs across 36
             breeds. A factor analysis yielded four factors interpreted
             as reflecting inhibitory control, communication, memory, and
             physical reasoning. Narrow-sense among-breed heritability
             estimates-reflecting the proportion of cognitive variance
             attributable to additive genetic variation-revealed that
             scores on the inhibitory control and communication factors
             were highly heritable (inhibitory control:
             h<sup>2</sup> = 0.70; communication:
             h<sup>2</sup> = 0.39), while memory and physical
             reasoning were less heritable (memory: h<sup>2</sup> = 0.17;
             physical reasoning: h<sup>2</sup> = 0.21). Although the
             heritability of inhibitory control is partially explained by
             body weight, controlling for breed-average weight still
             yields a high heritability estimate (h<sup>2</sup> = 0.50),
             while other factors are minimally affected. Our results
             indicate that cognitive phenotypes in dogs covary with breed
             relatedness and suggest that cognitive traits have strong
             potential to undergo selection. The highest heritabilities
             were observed for inhibitory control and communication, both
             of which are hypothesized to have been altered by
             domestication.},
   Doi = {10.1007/s10071-020-01400-4},
   Key = {fds350126}
}

@article{fds350795,
   Author = {Bray, EE and Gruen, ME and Gnanadesikan, GE and Horschler, DJ and Levy,
             KM and Kennedy, BS and Hare, BA and MacLean, EL},
   Title = {Cognitive characteristics of 8- to 10-week-old assistance
             dog puppies},
   Journal = {Animal Behaviour},
   Volume = {166},
   Pages = {193-206},
   Year = {2020},
   Month = {August},
   Abstract = {To characterize the early ontogeny of dog cognition, we
             tested 168 domestic dog, Canis familiaris, puppies (97
             females, 71 males; mean age = 9.2 weeks) in a novel test
             battery based on previous tasks developed and employed with
             adolescent and adult dogs. Our sample consisted of Labrador
             retrievers, golden retrievers and Labrador × golden
             retriever crosses from 65 different litters at Canine
             Companions for Independence, an organization that breeds,
             trains and places assistance dogs for people with
             disabilities. Puppies participated in a 3-day cognitive
             battery that consisted of 14 tasks measuring different
             cognitive abilities and temperament traits such as executive
             function (e.g. inhibitory control, reversal learning,
             working memory), use of social cues, sensory discriminations
             and reactivity to and recovery from novel situations. At
             8–10 weeks of age, and despite minimal experience with
             humans, puppies reliably used a variety of
             cooperative-communicative gestures from humans. Puppies
             accurately remembered the location of hidden food for delays
             of up to 20 s, and succeeded in a variety of visual,
             olfactory and auditory discrimination problems. They also
             showed some skill at executive function tasks requiring
             inhibitory control and reversal learning, although they
             scored lower on these tasks than is typical in adulthood.
             Taken together, our results confirm the early emergence of
             sensitivity to human communication in dogs and contextualize
             these skills within a broad array of other cognitive
             abilities measured at the same stage of ontogeny.},
   Doi = {10.1016/j.anbehav.2020.05.019},
   Key = {fds350795}
}

@article{fds349657,
   Author = {Watowich, MM and MacLean, EL and Hare, B and Call, J and Kaminski, J and Miklósi, Á and Snyder-Mackler, N},
   Title = {Age influences domestic dog cognitive performance
             independent of average breed lifespan.},
   Journal = {Animal cognition},
   Volume = {23},
   Number = {4},
   Pages = {795-805},
   Year = {2020},
   Month = {July},
   Abstract = {Across mammals, increased body size is positively associated
             with lifespan. However, within species, this relationship is
             inverted. This is well illustrated in dogs (Canis
             familiaris), where larger dogs exhibit accelerated life
             trajectories: growing faster and dying younger than smaller
             dogs. Similarly, some age-associated traits (e.g., growth
             rate and physiological pace of aging) exhibit accelerated
             trajectories in larger breeds. Yet, it is unknown whether
             cognitive performance also demonstrates an accelerated life
             course trajectory in larger dogs. Here, we measured
             cognitive development and aging in a cross-sectional study
             of over 4000 dogs from 66 breeds using nine memory and
             decision-making tasks performed by citizen scientists as
             part of the Dognition project. Specifically, we tested
             whether cognitive traits follow a compressed (accelerated)
             trajectory in larger dogs, or the same trajectory for all
             breeds, which would result in limited cognitive decline in
             larger breeds. We found that all breeds, regardless of size
             or lifespan, tended to follow the same quadratic trajectory
             of cognitive aging-with a period of cognitive development in
             early life and decline in later life. Taken together, our
             results suggest that cognitive performance follows similar
             age-related trajectories across dog breeds, despite
             remarkable variation in developmental rates and
             lifespan.},
   Doi = {10.1007/s10071-020-01385-0},
   Key = {fds349657}
}

@article{fds348897,
   Author = {Gruen, ME and White, P and Hare, B},
   Title = {Do dog breeds differ in pain sensitivity? Veterinarians and
             the public believe they do.},
   Journal = {PloS one},
   Volume = {15},
   Number = {3},
   Pages = {e0230315},
   Year = {2020},
   Month = {January},
   Abstract = {Humans do not respond to the pain of all humans equally;
             physical appearance and associated group identity affect how
             people respond to the pain of others. Here we ask if a
             similar differential response occurs when humans evaluate
             different individuals of another species. Beliefs about pain
             in pet dogs (Canis familiaris) provide a powerful test,
             since dogs vary so much in size, shape, and color, and are
             often associated with behavioral stereotypes. Using an
             on-line survey, we asked both the general public and
             veterinarians to rate pain sensitivity in 28 different dog
             breeds, identified only by their pictures. We found that
             both the general public and veterinarians rated smaller dogs
             (i.e. based on height and weight) as being more sensitive to
             pain; the general public respondents rated breeds associated
             with breed specific legislation as having lower pain
             sensitivity. While there is currently no known physiological
             basis for such breed-level differences, over 90% of
             respondents from both groups indicated belief in differences
             in pain sensitivity among dog breeds. We discuss how these
             results inform theories of human social discrimination and
             suggest that the perception of breed-level differences in
             pain sensitivity may affect the recognition and management
             of painful conditions in dogs.},
   Doi = {10.1371/journal.pone.0230315},
   Key = {fds348897}
}

@article{fds349331,
   Author = {Brooks, J and Kays, R and Hare, B},
   Title = {Coyotes living near cities are bolder: Implications for dog
             evolution and human-wildlife conflict},
   Journal = {Behaviour},
   Volume = {157},
   Number = {3-4},
   Pages = {289-313},
   Year = {2020},
   Month = {January},
   Abstract = {How animal populations adapt to human modified landscapes is
             central to understanding modern behavioural evolution and
             improving wildlife management. Coyotes (Canis latrans) have
             adapted to human activities and thrive in both rural and
             urban areas. Bolder coyotes showing reduced fear of humans
             and their artefacts may have an advantage in urban
             environments. We analysed the reactions of 636 coyotes to
             novel human artefacts (camera traps) at 575 sites across the
             state of North Carolina. Likelihood of a coyote approaching
             the camera increased with human housing density suggesting
             that urban coyotes are experiencing selection for boldness
             and becoming more attracted to human artefacts. This has
             implications for both human-wildlife conflict and theories
             of dog domestication. We also note physical traits in
             coyotes that could be the result of domestication-related
             selection pressures, or dog hybridization.},
   Doi = {10.1163/1568539X-bja10002},
   Key = {fds349331}
}

@misc{fds361337,
   Author = {Woods, V and Hare, B},
   Title = {Uncanny valley of the apes},
   Pages = {104-120},
   Booktitle = {Why We Love and Exploit Animals: Bridging Insights from
             Academia and Advocacy},
   Year = {2019},
   Month = {December},
   ISBN = {9780815396642},
   Abstract = {Humans have a complex emotional relationship with the other
             members of our great apes family. Great apes are appealing
             because of the close resemblances we share, but these
             resemblances can cause feelings of aversion and disgust. We
             propose that these feelings may stem from the uncanny valley
             - the point at which someone or something becomes almost,
             but not quite human. We argue that the uncanny valley has
             made great apes an effective tool for a particular type of
             dehumanization, known as simianization. Simianization has
             been especially prolonged and pervasive towards black
             people, dating from the transatlantic slave trade and
             continuing today. In the reverse direction, the humanness of
             great apes has made them a source of fascination, but has
             not saved them from extensive population decline and may
             have facilitated their exploitation. Preliminary research
             into decreasing the human-animal divide shows promise for
             mitigating the negative impact of simianization of people
             and for improving attitudes towards, and the welfare of,
             great apes.},
   Key = {fds361337}
}

@article{fds340823,
   Author = {Horschler, DJ and Hare, B and Call, J and Kaminski, J and Miklósi, Á and MacLean, EL},
   Title = {Absolute brain size predicts dog breed differences in
             executive function.},
   Journal = {Animal cognition},
   Volume = {22},
   Number = {2},
   Pages = {187-198},
   Year = {2019},
   Month = {March},
   Abstract = {Large-scale phylogenetic studies of animal cognition have
             revealed robust links between absolute brain volume and
             species differences in executive function. However, past
             comparative samples have been composed largely of primates,
             which are characterized by evolutionarily derived neural
             scaling rules. Therefore, it is currently unknown whether
             positive associations between brain volume and executive
             function reflect a broad-scale evolutionary phenomenon, or
             alternatively, a unique consequence of primate brain
             evolution. Domestic dogs provide a powerful opportunity for
             investigating this question due to their close genetic
             relatedness, but vast intraspecific variation. Using citizen
             science data on more than 7000 purebred dogs from 74 breeds,
             and controlling for genetic relatedness between breeds, we
             identify strong relationships between estimated absolute
             brain weight and breed differences in cognition.
             Specifically, larger-brained breeds performed significantly
             better on measures of short-term memory and self-control.
             However, the relationships between estimated brain weight
             and other cognitive measures varied widely, supporting
             domain-specific accounts of cognitive evolution. Our results
             suggest that evolutionary increases in brain size are
             positively associated with taxonomic differences in
             executive function, even in the absence of primate-like
             neuroanatomy. These findings also suggest that variation
             between dog breeds may present a powerful model for
             investigating correlated changes in neuroanatomy and
             cognition among closely related taxa.},
   Doi = {10.1007/s10071-018-01234-1},
   Key = {fds340823}
}

@misc{fds366381,
   Author = {Yamamoto, S and Tokuyama, N and Clay, Z and Hare,
             B},
   Title = {Chimpanzee and bonobo},
   Pages = {324-334},
   Booktitle = {Encyclopedia of Animal Behavior},
   Year = {2019},
   Month = {January},
   ISBN = {9780128132517},
   Abstract = {Chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) are
             both our evolutionary closest living relatives. Human and
             Pan lineages diverged around 7 million years ago, and the
             chimpanzee and the bonobo branched 1-2 million years ago.
             Accordingly, the two species have a lot of similarities in
             their appearance, behavior, and societies; however, research
             highlights some striking differences between these close
             sister species. There are a number of traits in which
             bonobos and chimpanzees are more similar to humans than they
             are each other have been recognized recently. This
             comparison provides an extremely powerful test of ideas
             about human uniqueness. Given that both species are equally
             related to us, balanced insights are needed from both
             chimpanzees and bonobos in order to understand the selective
             pressures which may have shaped the human mind. Here we
             concisely review their evolution, society, and cognition,
             and suggest its implication for the evolutionary processes
             by which cognitive traits evolve in apes.},
   Doi = {10.1016/B978-0-12-809633-8.90716-7},
   Key = {fds366381}
}

@article{fds366382,
   Author = {Barron, AB and Hare, B},
   Title = {Prosociality and a Sociosexual Hypothesis for the Evolution
             of Same-Sex Attraction in Humans.},
   Journal = {Frontiers in psychology},
   Volume = {10},
   Pages = {2955},
   Year = {2019},
   Month = {January},
   Abstract = {Human same-sex sexual attraction (SSSA) has long been
             considered to be an evolutionary puzzle. The trait is
             clearly biological: it is widespread and has a strong
             additive genetic basis, but how SSSA has evolved remains a
             subject of debate. Of itself, homosexual sexual behavior
             will not yield offspring, and consequently individuals
             expressing strong SSSA that are mostly or exclusively
             homosexual are presumed to have lower fitness and
             reproductive success. How then did the trait evolve, and how
             is it maintained in populations? Here we develop a novel
             argument for the evolution of SSSA that focuses on the
             likely adaptive social consequences of SSSA. We argue that
             same sex sexual attraction evolved as just one of a suite of
             traits responding to strong selection for ease of social
             integration or prosocial behavior. A strong driver of recent
             human behavioral evolution has been selection for reduced
             reactive aggression, increased social affiliation, social
             communication, and ease of social integration. In many
             prosocial mammals sex has adopted new social functions in
             contexts of social bonding, social reinforcement,
             appeasement, and play. We argue that for humans the social
             functions and benefits of sex apply to same-sex sexual
             behavior as well as heterosexual behavior. As a consequence
             we propose a degree of SSSA, was selected for in recent
             human evolution for its non-conceptive social benefits. We
             discuss how this hypothesis provides a better explanation
             for human sexual attractions and behavior than theories that
             invoke sexual inversion or single-locus genetic
             models.},
   Doi = {10.3389/fpsyg.2019.02955},
   Key = {fds366382}
}

@misc{fds372661,
   Author = {Yamamoto, S and Tokuyama, N and Clay, Z and Hare,
             B},
   Title = {Chimpanzee and Bonobo},
   Volume = {1},
   Pages = {V1-324-V1-334},
   Booktitle = {Encyclopedia of Animal Behavior, Second Edition: Volume
             1-5},
   Year = {2019},
   Month = {January},
   ISBN = {9780128132517},
   Abstract = {Chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) are
             both our evolutionary closest living relatives. Human and
             Pan lineages diverged around 7 million years ago, and the
             chimpanzee and the bonobo branched 1–2 million years ago.
             Accordingly, the two species have a lot of similarities in
             their appearance, behavior, and societies; however, research
             highlights some striking differences between these close
             sister species. There are a number of traits in which
             bonobos and chimpanzees are more similar to humans than they
             are each other have been recognized recently. This
             comparison provides an extremely powerful test of ideas
             about human uniqueness. Given that both species are equally
             related to us, balanced insights are needed from both
             chimpanzees and bonobos in order to understand the selective
             pressures which may have shaped the human mind. Here we
             concisely review their evolution, society, and cognition,
             and suggest its implication for the evolutionary processes
             by which cognitive traits evolve in apes.},
   Doi = {10.1016/B978-0-12-809633-8.90716-7},
   Key = {fds372661}
}

@article{fds335476,
   Author = {Lucca, K and MacLean, EL and Hare, B},
   Title = {The development and flexibility of gaze alternations in
             bonobos and chimpanzees.},
   Journal = {Developmental science},
   Volume = {21},
   Number = {4},
   Pages = {e12598},
   Year = {2018},
   Month = {July},
   Abstract = {Infants' early gaze alternations are one of their first
             steps towards a sophisticated understanding of the social
             world. This ability, to gaze alternate between an object of
             interest and another individual also attending to that
             object, has been considered foundational to the development
             of many complex social-cognitive abilities, such as theory
             of mind and language. However, to understand the evolution
             of these abilities, it is important to identify whether and
             how gaze alternations are used and develop in our closest
             living relatives, bonobos (Pan paniscus) and chimpanzees
             (Pan troglodytes). Here, we evaluated the development of
             gaze alternations in a large, developmental sample of
             bonobos (N = 17) and chimpanzees (N = 35). To assess the
             flexibility of ape gaze alternations, we tested whether they
             produced gaze alternations when requesting food from a human
             who was either visually attentive or visually inattentive.
             Similarly to human infants, both bonobos and chimpanzees
             produced gaze alternations, and did so more frequently when
             a human communicative partner was visually attentive.
             However, unlike humans, who gaze alternate frequently from
             early in development, chimpanzees did not begin to gaze
             alternate frequently until adulthood. Bonobos produced very
             few gaze alternations, regardless of age. Thus, it may be
             the early emergence of gaze alternations, as opposed gaze
             alternations themselves, that is derived in the human
             lineage. The distinctively early emergence of gaze
             alternations in humans may be a critical underpinning for
             the development of complex human social-cognitive
             abilities.},
   Doi = {10.1111/desc.12598},
   Key = {fds335476}
}

@article{fds331591,
   Author = {Hare, B},
   Title = {Domestication experiments reveal developmental link between
             friendliness and cognition},
   Journal = {Journal of Bioeconomics},
   Volume = {20},
   Number = {1},
   Pages = {159-163},
   Publisher = {Springer Nature},
   Year = {2018},
   Month = {April},
   Abstract = {The goal of economics is to understand human preferences.
             Most research focuses on adult humans and does not take an
             evolutionary approach. In biology experimental evolution has
             been able to shift the preferences of animals. As an
             example, artificial selection for friendly behavior toward
             humans results in a syndrome of changes that strongly
             resembles differences between wild and domestic animals.
             These domestication experiments have revealed precise
             genetic and neurobiological systems that are altered by the
             selection and linked through expanded windows of
             development. Similar evolutionary experiments selecting for
             a range of social, risk or discounting preferences could
             push economics toward consilience with biology. Prospects
             for a unified theory of economic behavior would be
             drastically improved.},
   Doi = {10.1007/s10818-017-9264-9},
   Key = {fds331591}
}

@article{fds331590,
   Author = {Krupenye, C and Hare, B},
   Title = {Bonobos Prefer Individuals that Hinder Others over Those
             that Help.},
   Journal = {Current biology : CB},
   Volume = {28},
   Number = {2},
   Pages = {280-286.e5},
   Year = {2018},
   Month = {January},
   Abstract = {Humans closely monitor others' cooperative relationships [1,
             2]. Children and adults willingly incur costs to reward
             helpers and punish non-helpers-even as bystanders [3-5].
             Already by 3 months, infants favor individuals that they
             observe helping others [6-8]. This early-emerging prosocial
             preference may be a derived motivation that accounts
             for many human forms of cooperation that occur beyond
             dyadic interactions and are not exhibited by other animals
             [9, 10]. As the most socially tolerant nonhuman ape [11-17]
             (but see [18]), bonobos (Pan paniscus) provide a powerful
             phylogenetic test of whether this trait is derived in
             humans. Bonobos are more tolerant than chimpanzees, can
             flexibly obtain food through cooperation, and voluntarily
             share food in captivity and the wild, even with strangers
             [11-17] (but see [18]). Their neural architecture exhibits a
             suite of characteristics associated with greater sensitivity
             to others [19, 20], and their sociality is hypothesized to
             have evolved due to selection against male aggression
             [21-23]. Here we show in four experiments that bonobos
             discriminated agents based on third-party interactions.
             However, they did not exhibit the human preference for
             helpers. Instead, they reliably favored a hinderer that
             obstructed another agent's goal (experiments 1-3). In a
             final study (experiment 4), bonobos also chose a dominant
             individual over a subordinate. Bonobos' interest in
             hinderers may reflect attraction to dominant individuals
             [24]. A preference for helpers over hinderers may therefore
             be derived in humans, supporting the hypothesis that
             prosocial preferences played a central role in the evolution
             of human development and cooperation.},
   Doi = {10.1016/j.cub.2017.11.061},
   Key = {fds331590}
}

@article{fds339286,
   Author = {MacLean, EL and Hare, B},
   Title = {Enhanced Selection of Assistance and Explosive Detection
             Dogs Using Cognitive Measures.},
   Journal = {Frontiers in veterinary science},
   Volume = {5},
   Pages = {236},
   Year = {2018},
   Month = {January},
   Abstract = {Working dogs play a variety of important roles, ranging from
             assisting individuals with disabilities, to explosive and
             medical detection work. Despite widespread demand, only a
             subset of dogs bred and trained for these roles ultimately
             succeed, creating a need for objective measures that can
             predict working dog aptitude. Most previous research has
             focused on temperamental characteristics of successful dogs.
             However, working dogs also face diverse cognitive challenges
             both in training, and throughout their working lives. We
             conducted a series of studies investigating the
             relationships between individual differences in dog
             cognition, and success as an assistance or detection dog.
             Assistance dogs (<i>N</i> = 164) and detection dogs
             (<i>N</i> = 222) were tested in the Dog Cognition Test
             Battery, a 25-item instrument probing diverse aspects of dog
             cognition. Through exploratory analyses we identified a
             subset of tasks associated with success in each training
             program, and developed shorter test batteries including only
             these measures. We then used predictive modeling in a
             prospective study with an independent sample of assistance
             dogs (<i>N</i> = 180), and conducted a replication study
             with an independent sample of detection dogs (<i>N</i> =
             90). In assistance dogs, models using data on individual
             differences in cognition predicted higher probabilities of
             success for dogs that ultimately succeeded in the program,
             than for those who did not. For the subset of dogs with
             predicted probabilities of success in the 4th quartile
             (highest predicted probability of success), model
             predictions were 86% accurate, on average. In both the
             exploratory and prospective studies, successful dogs were
             more likely to engage in eye contact with a human
             experimenter when faced with an unsolvable task, or when a
             joint social activity was disrupted. In detection dogs, we
             replicated our exploratory findings that the most successful
             dogs scored higher on measures of sensitivity to human
             communicative intentions, and two measures of short term
             memory. These findings suggest that that (1) individual
             differences in cognition contribute to variance in working
             dog success, and (2) that objective measures of dog
             cognition can be used to improve the processes through which
             working dogs are evaluated and selected.},
   Doi = {10.3389/fvets.2018.00236},
   Key = {fds339286}
}

@misc{fds335477,
   Author = {Hare, B and Yamamoto, S},
   Title = {Minding the bonobo mind},
   Pages = {1-14},
   Booktitle = {Bonobos: Unique in Mind, Brain, and Behavior},
   Publisher = {Oxford University Press},
   Year = {2018},
   Month = {January},
   ISBN = {9780198728511},
   Abstract = {In this chapter we introduce the central role the bonobo
             plays in testing evolutionary hypotheses regarding ape minds
             (including our own). The importance of bonobos has become
             apparent only recently with sustained fieldwork at multiple
             sites in the Congo Basin as well as the first direct
             quantitative comparisons between bonobos, chimpanzees and
             humans. This recent work has revealed a number of traits in
             which bonobos and chimpanzees are more similar to humans
             than they are to each other. This means that bonobos are
             crucial to determining the evolutionary processes by which
             cognitive traits evolved in our own lineage. Based on the
             evidence within, it becomes clear that one can no longer
             know chimpanzees or humans without also knowing bonobos. We
             argue this makes investing in bonobo research and improved
             protection for bonobos in captivity and the wild an even
             higher priority.},
   Doi = {10.1093/oso/9780198728511.003.0001},
   Key = {fds335477}
}

@misc{fds335478,
   Author = {Krupenye, C and MacLean, EL and Hare, B},
   Title = {Does the bonobo have a (chimpanzee-like) theory of
             mind?},
   Pages = {81-94},
   Booktitle = {Bonobos: Unique in Mind, Brain, and Behavior},
   Publisher = {Oxford University Press},
   Year = {2018},
   Month = {January},
   ISBN = {9780198728511},
   Abstract = {Theory of mind-the ability to reason about the thoughts and
             emotions of others-is central to what makes us human.
             Chimpanzees too appear to understand some psychological
             states. While less is known about bonobos, several lines of
             evidence suggest that the social-cognitive abilities of the
             two sister taxa may differ in key respects. This chapter
             outlines a framework to guide future research on bonobo
             social cognition based on the predictions of two potentially
             complementary hypotheses. The self-domestication hypothesis
             suggests that selection against aggression and for
             prosociality in bonobos may have impacted the ontogeny of
             their social-cognitive skills relative to chimpanzees. The
             empathizing-systemizing hypothesis links degree of prenatal
             brain masculinization, a potential result of
             self-domestication, to adult cognition. Specifically,
             relative feminization may yield more flexible theory of mind
             skills in bonobos than chimpanzees. Finally, directions for
             future study, including development of new paradigms that
             maximize ecological validity for bonobos, are
             discussed.},
   Doi = {10.1093/oso/9780198728511.003.0006},
   Key = {fds335478}
}

@misc{fds335479,
   Author = {Tan, J and Hare, B},
   Title = {Prosociality among non-kin in bonobos and chimpanzees
             compared},
   Pages = {140-154},
   Booktitle = {Bonobos: Unique in Mind, Brain, and Behavior},
   Publisher = {Oxford University Press},
   Year = {2018},
   Month = {January},
   ISBN = {9780198728511},
   Abstract = {Models of the origin of human prosociality towards non-kin
             have been primarily developed from chimpanzee studies.
             Substantially less effort has been made to consider the
             prosociality of bonobos. Like chimpanzees, bonobos cooperate
             with non-kin extensively but, unlike chimpanzees,
             immigrating members are central to bonobo cooperation. In
             experiments bonobos are tolerant during encounters with
             strangers and during co-feeding. They help strangers without
             immediate tangible reward, and forfeit monopolizable food to
             facilitate a physical interaction with them. Such
             prosociality seems proactive as it is not elicited by
             solicitation. Bonobos also seem to prefer sharing food over
             non-food objects, while chimpanzees reliably transfer
             non-food objects rather than food. These findings highlight
             the possibility that human sharing with strangers might have
             also evolved as a mutualistic endeavour to initiate a
             long-term partnership. Future models of human prosociality
             will need to incorporate findings from both Pan
             species.},
   Doi = {10.1093/oso/9780198728511.003.0010},
   Key = {fds335479}
}

@book{fds335480,
   Author = {Hare, B and Yamamoto, S},
   Title = {Bonobos: Unique in mind, brain, and behavior},
   Pages = {1-290},
   Publisher = {Oxford University Press},
   Year = {2018},
   Month = {January},
   ISBN = {9780198728511},
   Abstract = {During the past decade there has been an explosion of
             scientific interest in the bonobo (Pan paniscus). This
             research has revealed exactly how unique bonobos are in
             their minds, brains and behavior. This book makes clear the
             central role that bonobos play as we test hypotheses
             relating to the processes by which evolution shapes ape
             cognition (including our own species). The book’s
             introduction describes the recent interest into bonobo
             cognition while briefly reviewing the history of research
             with bonobos. To place this new work in its evolutionary
             contexts, researchers from the two most active bonobo field
             sites start the book by reporting on recent discoveries
             regarding the social behavior of bonobos. The following
             three sections explore social cognition and behavior of
             bonobos from viewpoints of development, communication, and
             cooperation. Then the fifth section considers the cognitive
             abilities deployed by bonobos as they forage for and process
             food. The sixth section focuses on large scale comparison of
             bonobos to both chimpanzees and humans in their cognitive
             abilities and brain anatomy. Finally, the last two sections
             include chapters exploring the past and future of the
             bonobos, providing novel perspectives on how to promote the
             survival of this highly endangered species. These chapters
             are contributed by experts representing diverse disciplines
             and take together study bonobos living in a range of
             settings. They present overwhelming evidence for bonobo
             uniqueness and the new understanding this creates will
             contribute to a bright future for bonobos living in
             captivity and the wild.},
   Doi = {10.1093/oso/9780198728511.001.0001},
   Key = {fds335480}
}

@misc{fds335481,
   Author = {Faust, LJ and André, C and Belais, R and Minesi, F and Pereboom, Z and Rodriguez, K and Hare, B},
   Title = {Bonobo population dynamics: Past patterns and future
             predictions for the Lola ya Bonobo population using
             demographic modelling},
   Pages = {266-274},
   Booktitle = {Bonobos: Unique in Mind, Brain, and Behavior},
   Publisher = {Oxford University Press},
   Year = {2018},
   Month = {January},
   ISBN = {9780198728511},
   Abstract = {Wildlife sanctuaries rescue, rehabilitate, reintroduce and
             provide life-long care for orphaned and injured animals.
             Understanding a sanctuary’s population dynamics—patterns
             in arrival, mortality and projected changes in population
             size—allows careful planning for future needs. Building on
             previous work on the population dynamics of chimpanzees (Pan
             troglodytes) in sanctuaries of the Pan African Sanctuary
             Alliance (PASA; Faust et al. 2011), this chapter extends
             analyses to the only PASA bonobo sanctuary. Its authors
             analysed historic demographic patterns and projected future
             population dynamics using an individual-based demographic
             model. The population has been growing at 6.7 per cent per
             year, driven by arrivals of new individuals (mean = 5.5
             arrivals per year). Several model scenarios projecting
             varying arrival rates, releases and breeding scenarios
             clarify potential future growth trajectories for the
             sanctuary. This research illustrates how data on historic
             dynamics can be modelled to inform future sanctuary capacity
             and management needs.},
   Doi = {10.1093/oso/9780198728511.003.0018},
   Key = {fds335481}
}

@misc{fds335482,
   Author = {Walker, K and Hare, B},
   Title = {Bonobo baby dominance: Did female defense of offspring lead
             to reduced male aggression?},
   Pages = {49-64},
   Booktitle = {Bonobos: Unique in Mind, Brain, and Behavior},
   Publisher = {Oxford University Press},
   Year = {2018},
   Month = {January},
   ISBN = {9780198728511},
   Abstract = {The dominance style of bonobos presents an evolutionary
             puzzle. Bonobos are not male dominant but female bonobos do
             not show traits typical of female-dominant species. This
             chapter proposes the offspring dominance hypothesis (ODH) as
             a potential solution. ODH suggests the social system of
             bonobos evolved as a defence against infanticide and is not
             due to pressure to monopolize resources. Females that
             prevented aggression towards offspring and preferred mating
             with less aggressive males were most successful. Supporting
             ODH, during observations at Lola ya Bonobo Sanctuary it was
             found that: 1) adult male bonobos are rarely aggressive
             towards offspring with mothers, 2) some mother-reared
             juvenile bonobos attain rank higher than adult males and 3)
             mother-reared offspring often socially interact with adult
             males without their mothers nearby. These preliminary
             findings provide initial support that the bonobo social
             system evolved due to fitness advantages of effectively
             protecting offspring against consequences of male
             aggression.},
   Doi = {10.1093/oso/9780198728511.003.0004},
   Key = {fds335482}
}

@misc{fds335483,
   Author = {Hare, B and Woods, V},
   Title = {Cognitive comparisons of genus Pan support bonobo
             self-domestication},
   Pages = {214-232},
   Booktitle = {Bonobos: Unique in Mind, Brain, and Behavior},
   Publisher = {Oxford University Press},
   Year = {2018},
   Month = {January},
   ISBN = {9780198728511},
   Abstract = {The self-domestication hypothesis (SDH) suggests bonobo
             psychology evolved due to selection against aggression and
             in favour of prosociality. This hypothesis was formulated
             based on similarities between bonobos and domesticated
             animals. This chapter reviews the first generation of
             quantitative research that supports the predictions of the
             SDH. Similar to domestic animals, bonobos are prosocial
             towards strangers, are more flexible with cooperative
             problems, are more responsive to social cues and show
             expanded windows of development compared to their closest
             relatives, chimpanzees. A preliminary comparison of bonobo
             and chimpanzee infants suggests that when hearing a
             stranger, bonobos have a xenophilic response while
             chimpanzees have a xenophobic response. The chapter explores
             why the research with bonobos has implications for theories
             of both human and animal cognitive evolution, and why
             bonobos will be central in studying evolutionary processes
             that lead to cognitive change.},
   Doi = {10.1093/oso/9780198728511.003.0015},
   Key = {fds335483}
}

@article{fds329757,
   Author = {Tan, J and Ariely, D and Hare, B},
   Title = {Bonobos respond prosocially toward members of other
             groups.},
   Journal = {Scientific reports},
   Volume = {7},
   Number = {1},
   Pages = {14733},
   Year = {2017},
   Month = {November},
   Abstract = {Modern humans live in an "exploded" network with unusually
             large circles of trust that form due to prosociality toward
             unfamiliar people (i.e. xenophilia). In a set of experiments
             we demonstrate that semi-free ranging bonobos (Pan paniscus)
             - both juveniles and young adults - also show spontaneous
             responses consistent with xenophilia. Bonobos voluntarily
             aided an unfamiliar, non-group member in obtaining food even
             when he/she did not make overt requests for help. Bonobos
             also showed evidence for involuntary, contagious yawning in
             response to videos of yawning conspecifics who were complete
             strangers. These experiments reveal that xenophilia in
             bonobos can be unselfish, proactive and automatic. They
             support the first impression hypothesis that suggests
             xenophilia can evolve through individual selection in social
             species whenever the benefits of building new bonds outweigh
             the costs. Xenophilia likely evolved in bonobos as the risk
             of intergroup aggression dissipated and the benefits of
             bonding between immigrating members increased. Our findings
             also mean the human potential for xenophilia is either
             evolutionarily shared or convergent with bonobos and not
             unique to our species as previously proposed.},
   Doi = {10.1038/s41598-017-15320-w},
   Key = {fds329757}
}

@article{fds324356,
   Author = {MacLean, EL and Herrmann, E and Suchindran, S and Hare,
             B},
   Title = {Individual differences in cooperative communicative skills
             are more similar between dogs and humans than
             chimpanzees},
   Journal = {Animal Behaviour},
   Volume = {126},
   Pages = {41-51},
   Publisher = {Elsevier BV},
   Year = {2017},
   Month = {April},
   Abstract = {By 2.5 years of age humans are more skilful than other apes
             on a set of social, but not nonsocial, cognitive tasks.
             Individual differences in human infants, but not
             chimpanzees, Pan troglodytes, are also explained by
             correlated variance in these cooperative communicative
             skills. Relative to nonhuman apes, domestic dogs, Canis
             familiaris, perform more like human infants in cooperative
             communicative tasks, but it is unknown whether dog and human
             cognition share a similar underlying structure. We tested
             552 dogs in a large-scale test battery modelled after
             similar work with humans and nonhuman apes. Unlike
             chimpanzees, but similarly to humans, individual differences
             in dogs were explained by correlated variance in skills for
             solving cooperative communicative problems. Direct
             comparisons of data from all three species revealed similar
             patterns of individual differences in cooperative
             communication between human infants (N = 105) and domestic
             dogs (N = 430), which were not observed in chimpanzees
             (N = 106). Future research will be needed to examine
             whether the observed similarities are a result of similar
             psychological mechanisms and evolutionary processes in the
             dog and human lineages.},
   Doi = {10.1016/j.anbehav.2017.01.005},
   Key = {fds324356}
}

@article{fds323646,
   Author = {Hare, B},
   Title = {Survival of the Friendliest: Homo sapiens Evolved via
             Selection for Prosociality.},
   Journal = {Annual review of psychology},
   Volume = {68},
   Pages = {155-186},
   Year = {2017},
   Month = {January},
   Abstract = {The challenge of studying human cognitive evolution is
             identifying unique features of our intelligence while
             explaining the processes by which they arose. Comparisons
             with nonhuman apes point to our early-emerging
             cooperative-communicative abilities as crucial to the
             evolution of all forms of human cultural cognition,
             including language. The human self-domestication hypothesis
             proposes that these early-emerging social skills evolved
             when natural selection favored increased in-group
             prosociality over aggression in late human evolution. As a
             by-product of this selection, humans are predicted to show
             traits of the domestication syndrome observed in other
             domestic animals. In reviewing comparative, developmental,
             neurobiological, and paleoanthropological research,
             compelling evidence emerges for the predicted relationship
             between unique human mentalizing abilities, tolerance, and
             the domestication syndrome in humans. This synthesis
             includes a review of the first a priori test of the
             self-domestication hypothesis as well as predictions for
             future tests.},
   Doi = {10.1146/annurev-psych-010416-044201},
   Key = {fds323646}
}

@article{fds322443,
   Author = {Reddy, RB and Krupenye, C and MacLean, EL and Hare,
             B},
   Title = {No evidence for contagious yawning in lemurs.},
   Journal = {Animal cognition},
   Volume = {19},
   Number = {5},
   Pages = {889-898},
   Year = {2016},
   Month = {September},
   Abstract = {Among some haplorhine primates, including humans, relaxed
             yawns spread contagiously. Such contagious yawning has been
             linked to social bonds and empathy in some species. However,
             no studies have investigated contagious yawning in
             strepsirhines. We conducted an experimental study of
             contagious yawning in strepsirhines, testing ring-tailed and
             ruffed lemurs (n = 24) in a paradigm similar to one that
             has induced contagious yawning in haplorhines. First, in a
             control experiment, we investigated whether lemurs responded
             to projected video content in general (experiment 1). We
             showed them two videos to which we expected differential
             responses: one featured a terrestrial predator and the other
             a caretaker holding food. Next, to test for yawn contagion,
             we showed individual lemurs life-size video projections of
             groupmates and conspecific strangers yawning, and control
             footage of the same individuals at rest (experiment 2).
             Then, to examine whether a group context might enhance or
             allow for contagion, we exposed subjects to the same videos
             in a group setting (experiment 3). Lemurs produced alarm
             vocalizations and moved upward while viewing the predator,
             but not the caretaker, demonstrating that they do perceive
             video content meaningfully. However, lemurs did not yawn in
             response to yawning stimuli when tested alone, or with their
             groupmates. This study provides preliminary evidence that
             lemurs do not respond to yawning stimuli similarly to
             haplorhines, and suggests that this behavior may have
             evolved or become more exaggerated in haplorhines after the
             two major primate lineages split.},
   Doi = {10.1007/s10071-016-0986-1},
   Key = {fds322443}
}

@article{fds322444,
   Author = {Pontzer, H and Brown, MH and Raichlen, DA and Dunsworth, H and Hare, B and Walker, K and Luke, A and Dugas, LR and Durazo-Arvizu, R and Schoeller,
             D and Plange-Rhule, J and Bovet, P and Forrester, TE and Lambert, EV and Thompson, ME and Shumaker, RW and Ross, SR},
   Title = {Metabolic acceleration and the evolution of human brain size
             and life history.},
   Journal = {Nature},
   Volume = {533},
   Number = {7603},
   Pages = {390-392},
   Year = {2016},
   Month = {May},
   Abstract = {Humans are distinguished from the other living apes in
             having larger brains and an unusual life history that
             combines high reproductive output with slow childhood growth
             and exceptional longevity. This suite of derived traits
             suggests major changes in energy expenditure and allocation
             in the human lineage, but direct measures of human and ape
             metabolism are needed to compare evolved energy strategies
             among hominoids. Here we used doubly labelled water
             measurements of total energy expenditure (TEE; kcal day(-1))
             in humans, chimpanzees, bonobos, gorillas and orangutans to
             test the hypothesis that the human lineage has experienced
             an acceleration in metabolic rate, providing energy for
             larger brains and faster reproduction without sacrificing
             maintenance and longevity. In multivariate regressions
             including body size and physical activity, human TEE
             exceeded that of chimpanzees and bonobos, gorillas and
             orangutans by approximately 400, 635 and 820 kcal day(-1),
             respectively, readily accommodating the cost of humans'
             greater brain size and reproductive output. Much of the
             increase in TEE is attributable to humans' greater basal
             metabolic rate (kcal day(-1)), indicating increased organ
             metabolic activity. Humans also had the greatest body fat
             percentage. An increased metabolic rate, along with changes
             in energy allocation, was crucial in the evolution of human
             brain size and life history.},
   Doi = {10.1038/nature17654},
   Key = {fds322444}
}

@article{fds332975,
   Author = {Rosati, AG and Hare, B},
   Title = {Reward currency modulates human risk preferences},
   Journal = {Evolution and Human Behavior},
   Volume = {37},
   Number = {2},
   Pages = {159-168},
   Publisher = {Elsevier BV},
   Year = {2016},
   Month = {March},
   Abstract = {Monetary and biological rewards differ in many ways. Yet
             studies of human decision-making typically involve money,
             whereas nonhuman studies involve food. We therefore examined
             how context shifts human risk preferences to illuminate the
             evolution of decision-making. First, we assessed peoples'
             risk preferences across food, prizes, and money in a task
             where individuals received real rewards and learned about
             payoffs through experience. We found that people were
             relatively more risk-seeking for both food and prizes
             compared to money-indicating that people may treat abstract
             reward markers differently from concrete rewards. Second, we
             compared human risk preferences for food with that of our
             closest phylogenetic relatives, chimpanzees (Pan
             troglodytes) and bonobos (Pan paniscus), in order to
             illuminate the evolutionary origins of human decision-making
             strategies. In fact, human and chimpanzees were both
             relatively more risk-seeking compared to bonobos. Finally,
             we investigated why people respond differently to money
             versus concrete rewards when making decisions. We found that
             people were more risk-prone when making decisions about
             money that was constrained as a store of value, compared to
             money that could be freely exchanged. This shows that people
             are sensitive to money's usefulness as a store of value that
             can be used to acquire other types of rewards. Our results
             indicate that humans exhibit different preferences when
             making risky decisions about money versus food, an important
             consideration for comparative research. Furthermore,
             different psychological processes may underpin decisions
             about abstract rewards compared to concrete
             rewards.},
   Doi = {10.1016/j.evolhumbehav.2015.10.003},
   Key = {fds332975}
}

@article{fds322445,
   Author = {Krupenye, C and Rosati, AG and Hare, B},
   Title = {What's in a frame? Response to Kanngiesser & Woike
             (2016).},
   Journal = {Biology letters},
   Volume = {12},
   Number = {1},
   Pages = {20150959},
   Year = {2016},
   Month = {January},
   Doi = {10.1098/rsbl.2015.0959},
   Key = {fds322445}
}

@article{fds240356,
   Author = {Stewart, L and MacLean, EL and Ivy, D and Woods, V and Cohen, E and Rodriguez, K and McIntyre, M and Mukherjee, S and Call, J and Kaminski,
             J and Miklósi, Á and Wrangham, RW and Hare, B},
   Title = {Citizen Science as a New Tool in Dog Cognition
             Research},
   Journal = {PLoS ONE},
   Volume = {10},
   Number = {9},
   Pages = {e0135176},
   Publisher = {Public Library of Science},
   Year = {2015},
   Month = {September},
   url = {http://hdl.handle.net/10161/10647 Duke open access
             repository},
   Abstract = {<p>Family dogs and dog owners offer a potentially powerful
             way to conduct citizen science to answer questions about
             animal behavior that are difficult to answer with more
             conventional approaches. Here we evaluate the quality of the
             first data on dog cognition collected by citizen scientists
             using the <italic>Dognition</italic>.<italic>com</italic>
             website. We conducted analyses to understand if data
             generated by over 500 citizen scientists replicates
             internally and in comparison to previously published
             findings. Half of participants participated for free while
             the other half paid for access. The website provided each
             participant a temperament questionnaire and instructions on
             how to conduct a series of ten cognitive tests.
             Participation required internet access, a dog and some
             common household items. Participants could record their
             responses on any PC, tablet or smartphone from anywhere in
             the world and data were retained on servers. Results from
             citizen scientists and their dogs replicated a number of
             previously described phenomena from conventional lab-based
             research. There was little evidence that citizen scientists
             manipulated their results. To illustrate the potential uses
             of relatively large samples of citizen science data, we then
             used factor analysis to examine individual differences
             across the cognitive tasks. The data were best explained by
             multiple factors in support of the hypothesis that
             nonhumans, including dogs, can evolve multiple cognitive
             domains that vary independently. This analysis suggests that
             in the future, citizen scientists will generate useful
             datasets that test hypotheses and answer questions as a
             complement to conventional laboratory techniques used to
             study dog psychology.</p>},
   Doi = {10.1371/journal.pone.0135176},
   Key = {fds240356}
}

@article{fds240357,
   Author = {Bray, E and MacLean, E and Hare, B},
   Title = {Increasing arousal enhances inhibitory control in calm but
             not excitable dogs},
   Journal = {Animal Cognition},
   Volume = {18},
   Number = {6},
   Pages = {1-13},
   Publisher = {Springer Berlin Heidelberg},
   Year = {2015},
   Month = {July},
   ISSN = {1435-9448},
   url = {http://hdl.handle.net/10161/10608 Duke open access
             repository},
   Abstract = {The emotional-reactivity hypothesis proposes that
             problem-solving abilities can be constrained by temperament,
             within and across species. One way to test this hypothesis
             is with the predictions of the Yerkes-Dodson law. The law
             posits that arousal level, a component of temperament,
             affects problem solving in an inverted U-shaped
             relationship: Optimal performance is reached at intermediate
             levels of arousal and impeded by high and low levels. Thus,
             a powerful test of the emotional-reactivity hypothesis is to
             compare cognitive performance in dog populations that have
             been bred and trained based in part on their arousal levels.
             We therefore compared a group of pet dogs to a group of
             assistance dogs bred and trained for low arousal (N = 106)
             on a task of inhibitory control involving a detour response.
             Consistent with the Yerkes-Dodson law, assistance dogs,
             which began the test with lower levels of baseline arousal,
             showed improvements when arousal was artificially increased.
             In contrast, pet dogs, which began the test with higher
             levels of baseline arousal, were negatively affected when
             their arousal was increased. Furthermore, the dogs' baseline
             levels of arousal, as measured in their rate of tail
             wagging, differed by population in the expected directions.
             Low-arousal assistance dogs showed the most inhibition in a
             detour task when humans eagerly encouraged them, while more
             highly aroused pet dogs performed worst on the same task
             with strong encouragement. Our findings support the
             hypothesis that selection on temperament can have important
             implications for cognitive performance.},
   Doi = {10.1007/s10071-015-0901-1},
   Key = {fds240357}
}

@article{fds240360,
   Author = {Reddy, RB and MacLean, EL and Sandel, AA and Hare,
             B},
   Title = {Social inhibitory control in five lemur species.},
   Journal = {Primates; journal of primatology},
   Volume = {56},
   Number = {3},
   Pages = {241-252},
   Year = {2015},
   Month = {July},
   ISSN = {0032-8332},
   Abstract = {We tested five lemur species-ring-tailed lemurs, ruffed
             lemurs, mongoose lemurs, black lemurs, and Coquerel's
             sifakas-(N = 52) in an experiment that evaluated skills
             for inhibitory control in a social context. First, two human
             experimenters presented identical food rewards; the
             "generous" experimenter allowed the subject to eat from her
             hand, whereas the "competitive" experimenter always withheld
             the reward. Lemurs quickly learned to approach the generous
             experimenter and avoid the competitive one. In the
             inhibition test phase, we endowed the competitive
             experimenter with a more valuable food reward but the
             competitive experimenter continued to withhold food from the
             subject. Thus, lemurs were required to inhibit approaching
             the more desirable reward in favor of the lesser but
             obtainable reward presented by the generous experimenter. In
             test trials, lemurs' tendency to approach the competitive
             experimenter increased from the reputation phase,
             demonstrating sensitivity to the experimental manipulation.
             However, subjects approached the larger reward less
             frequently in test trials compared with pretest
             food-preference trials, evidencing some capacity for
             inhibitory control in this context. Despite differences in
             sociality and ecology, the five lemur species did not differ
             in this ability. Although the study did not uncover species
             differences, this experimental task may provide a useful
             measure of social inhibition in broader comparative
             studies.},
   Doi = {10.1007/s10329-015-0467-1},
   Key = {fds240360}
}

@article{fds240359,
   Author = {MacLean, EL and Hare, B},
   Title = {Evolution. Dogs hijack the human bonding
             pathway.},
   Journal = {Science (New York, N.Y.)},
   Volume = {348},
   Number = {6232},
   Pages = {280-281},
   Year = {2015},
   Month = {April},
   ISSN = {0036-8075},
   Doi = {10.1126/science.aab1200},
   Key = {fds240359}
}

@article{fds240361,
   Author = {MacLean, EL and Hare, B},
   Title = {Bonobos and chimpanzees exploit helpful but not prohibitive
             gestures},
   Journal = {Behaviour},
   Volume = {152},
   Number = {3-4},
   Pages = {493-520},
   Publisher = {BRILL},
   Year = {2015},
   Month = {February},
   ISSN = {0005-7959},
   Abstract = {Previous research has shown that chimpanzees exploit the
             behavior of humans and conspecifics more readily in a
             competitive than a cooperative context. However, it is
             unknown whether bonobos, who outperform chimpanzees in some
             cooperative tasks, also show greater cognitive flexibility
             in competitive contexts. Here we tested the
             cooperative-competitive hypothesis further by comparing
             bonobos and chimpanzees in a series of tasks where a human
             gesture indicated the correct (cooperative) or incorrect
             (competitive) choice. A human either pointed cooperatively
             to the object a subject should choose, or competitively to
             the object subjects should avoid choosing. In contrast to
             previous research, subjects were most skilled at choosing
             the correct location when the communicator was cooperative
             and there were no major differences between bonobos and
             chimpanzees. Analysis of gaze direction revealed that in
             some cases subjects visually followed the direction of the
             experimenter's gesture despite choosing incorrectly,
             dissociating gesture following from gesture comprehension.
             This supports the hypothesis that, unlike human children,
             nonhuman apes respond to the direction of social gestures
             more readily than they understand the communicative
             intentions underlying them.We evaluate these findings in
             regard to previous studies comparing the cooperative and
             communicative skills of bonobos and chimpanzees.},
   Doi = {10.1163/1568539X-00003203},
   Key = {fds240361}
}

@article{fds240362,
   Author = {Schroepfer-Walker, K and Wobber, V and Hare, B},
   Title = {Experimental evidence that grooming and play are social
             currency in bonobos and chimpanzees},
   Journal = {Behaviour},
   Volume = {152},
   Number = {3-4},
   Pages = {545-562},
   Publisher = {BRILL},
   Year = {2015},
   Month = {February},
   ISSN = {0005-7959},
   Abstract = {While natural observations show apes use grooming and play
             as social currency, no experimental manipulations have been
             carried out to measure the effects of these behaviours on
             relationship formation in apes. While previous experiments
             have demonstrated apes quickly learn the identity of
             individuals who will provide food in a variety of
             cooperative and non-cooperative situations, no experiment
             has ever examined how grooming and play might shape the
             preferences of apes for different individuals. We gave a
             group bonobos (N = 25) and chimpanzees (N = 30) a choice
             between an unfamiliar human who had recently groomed or
             played with them and one who had not. Both species showed a
             preference for the unfamiliar human that had interacted with
             them over the one who did not. The effect was largely driven
             by the males of both species while interacting with females
             showed little effect on their preferences for unfamiliar
             humans. Subjects showed this preference even though they
             only had social interactions with one of the unfamiliar
             humans for a few minutes before each trial and their choices
             were not rewarded with food differentially. Our results
             support the long held idea that grooming and play act as a
             form of social currency in great apes (and likely many other
             species) that can rapidly shape social relationships,
             particularly between unfamiliar individuals.},
   Doi = {10.1163/1568539X-00003258},
   Key = {fds240362}
}

@article{fds240363,
   Author = {Tan, J and Kwetuenda, S and Hare, B},
   Title = {Preference or paradigm? Bonobos show no evidence of
             other-regard in the standard prosocial choice
             task},
   Journal = {Behaviour},
   Volume = {152},
   Number = {3-4},
   Pages = {521-544},
   Publisher = {BRILL},
   Year = {2015},
   Month = {February},
   ISSN = {0005-7959},
   Abstract = {Bonobos are the only ape species, other than humans, that
             have demonstrated prosocial behaviors toward groupmates and
             strangers. However, bonobos have not been tested in the most
             frequently used test of prosociality in animals. The current
             study tested the other-regarding preferences of bonobos in
             two experiments using the prosocial choice task. In the
             first experiment subjects preferred a food option that would
             benefit both themselves and another bonobo. This preference
             was likely the result of a location bias developed in the
             pretest since they showed the same preference in the
             non-social control condition within test sessions. A second
             experiment was designed to help subjects overcome this bias
             that might interfere with their social choices. Bonobos
             again did not prefer to choose the prosocial option.
             However, results suggest constraints of this paradigm in
             revealing social preferences. In discussing our results we
             consider why bonobos show robust prosocial preferences in
             other paradigms but not here. While others have suggested
             that such contradictory results might suggest interesting
             motivational or cognitive differences between humans and
             non-humans, we propose that the current 'standard' paradigm
             has failed validation due to three methodological
             constraints. Across the dozens of studies completed few have
             demonstrated that non-human subjects understand the causal
             properties of the apparatus, non-social biases quickly
             develop in inadequately counterbalanced pretests that
             typically explain subjects' choices in the test, and even
             human children found this choice task too cognitively
             demanding to consistently show prosocial preferences. We
             suggest it is time to consider switching to a variety of
             more powerful and valid measures.},
   Doi = {10.1163/1568539X-00003230},
   Key = {fds240363}
}

@article{fds240364,
   Author = {Hare, B and Yamamoto, S},
   Title = {Moving bonobos off the scientifically endangered
             list},
   Journal = {Behaviour},
   Volume = {152},
   Number = {3-4},
   Pages = {247-258},
   Publisher = {BRILL},
   Year = {2015},
   Month = {February},
   ISSN = {0005-7959},
   Abstract = {This Special Issue of Behaviour includes twelve novel
             empirical papers focusing on the behaviour and cognition of
             both captive and wild bonobos (Pan paniscus). As our species
             less known closest relative, the bonobo has gone from being
             little studied to increasingly popular as a species of focus
             over the past decade. We suggest that bonobos are ready to
             come off the scientific endangered list as a result. This
             Special Issue is exhibit A in showing that a renaissance in
             bonobo research is well underway. In this Editorial we
             review a number of traits in which bonobos and chimpanzees
             are more similar to humans than they are each other.We show
             how this means that bonobos provide an extremely powerful
             test of ideas about human uniqueness as well as being
             crucial to determining the evolutionary processes by which
             cognitive traits evolve in apes. This introduction places
             the twelve empirical contributions within the Special Issue
             in the larger evolutionary context to which they contribute.
             Overall this Special Issue demonstrates how anyone
             interested in understanding humans or chimpanzees must also
             know bonobos.},
   Doi = {10.1163/1568539X-00003263},
   Key = {fds240364}
}

@article{fds240365,
   Author = {Krupenye, C and Rosati, AG and Hare, B},
   Title = {Bonobos and chimpanzees exhibit human-like framing
             effects.},
   Journal = {Biology letters},
   Volume = {11},
   Number = {2},
   Pages = {20140527},
   Year = {2015},
   Month = {February},
   ISSN = {1744-9561},
   Abstract = {Humans exhibit framing effects when making choices,
             appraising decisions involving losses differently from those
             involving gains. To directly test for the evolutionary
             origin of this bias, we examined decision-making in humans'
             closest living relatives: bonobos (Pan paniscus) and
             chimpanzees (Pan troglodytes). We presented the largest
             sample of non-humans to date (n = 40) with a simple task
             requiring minimal experience. Apes made choices between a
             'framed' option that provided preferred food, and an
             alternative option that provided a constant amount of
             intermediately preferred food. In the gain condition, apes
             experienced a positive 'gain' event in which the framed
             option was initially presented as one piece of food but
             sometimes was augmented to two. In the loss condition, apes
             experienced a negative 'loss' event in which they initially
             saw two pieces but sometimes received only one. Both
             conditions provided equal pay-offs, but apes chose the
             framed option more often in the positive 'gain' frame.
             Moreover, male apes were more susceptible to framing than
             were females. These results suggest that some human economic
             biases are shared through common descent with other apes and
             highlight the importance of comparative work in
             understanding the origins of individual differences in human
             choice.},
   Doi = {10.1098/rsbl.2014.0527},
   Key = {fds240365}
}

@article{fds240367,
   Author = {MacLean, EL and Krupenye, C and Hare, B},
   Title = {Dogs (Canis familiaris) account for body orientation but not
             visual barriers when responding to pointing
             gestures.},
   Journal = {Journal of comparative psychology (Washington, D.C. :
             1983)},
   Volume = {128},
   Number = {3},
   Pages = {285-297},
   Year = {2014},
   Month = {August},
   ISSN = {0735-7036},
   Abstract = {In a series of four experiments we investigated whether dogs
             use information about a human's visual perspective when
             responding to pointing gestures. While there is evidence
             that dogs may know what humans can and cannot see, and that
             they flexibly use human communicative gestures, it is
             unknown if they can integrate these two skills. In
             Experiment 1 we first determined that dogs were capable of
             using basic information about a human's body orientation
             (indicative of her visual perspective) in a point following
             context. Subjects were familiarized with experimenters who
             either faced the dog and accurately indicated the location
             of hidden food, or faced away from the dog and (falsely)
             indicated the unbaited container. In test trials these cues
             were pitted against one another and dogs tended to follow
             the gesture from the individual who faced them while
             pointing. In Experiments 2-4 the experimenter pointed
             ambiguously toward two possible locations where food could
             be hidden. On test trials a visual barrier occluded the
             pointer's view of one container, while dogs could always see
             both containers. We predicted that if dogs could take the
             pointer's visual perspective they should search in the only
             container visible to the pointer. This hypothesis was
             supported only in Experiment 2. We conclude that while dogs
             are skilled both at following human gestures, and exploiting
             information about others' visual perspectives, they may not
             integrate these skills in the manner characteristic of human
             children.},
   Doi = {10.1037/a0035742},
   Key = {fds240367}
}

@article{fds240373,
   Author = {Rosati, AG and Rodriguez, K and Hare, B},
   Title = {The ecology of spatial memory in four lemur
             species.},
   Journal = {Animal cognition},
   Volume = {17},
   Number = {4},
   Pages = {947-961},
   Year = {2014},
   Month = {July},
   ISSN = {1435-9448},
   Abstract = {Evolutionary theories suggest that ecology is a major factor
             shaping cognition in primates. However, there have been few
             systematic tests of spatial memory abilities involving
             multiple primate species. Here, we examine spatial memory
             skills in four strepsirrhine primates that vary in level of
             frugivory: ruffed lemurs (Varecia sp.), ring-tailed lemurs
             (Lemur catta), mongoose lemurs (Eulemur mongoz), and
             Coquerel's sifakas (Propithecus coquereli). We compare these
             species across three studies targeting different aspects of
             spatial memory: recall after a long-delay, learning
             mechanisms supporting memory and recall of multiple
             locations in a complex environment. We find that ruffed
             lemurs, the most frugivorous species, consistently showed
             more robust spatial memory than the other species across
             tasks-especially in comparison with sifakas, the most
             folivorous species. We discuss these results in terms of the
             importance of considering both ecological and social factors
             as complementary explanations for the evolution of primate
             cognitive skills.},
   Doi = {10.1007/s10071-014-0727-2},
   Key = {fds240373}
}

@article{fds240371,
   Author = {MacLean, EL and Hare, B and Nunn, CL and Addessi, E and Amici, F and Anderson, RC and Aureli, F and Baker, JM and Bania, AE and Barnard, AM and Boogert, NJ and Brannon, EM and Bray, EE and Bray, J and Brent, LJN and Burkart, JM and Call, J and Cantlon, JF and Cheke, LG and Clayton, NS and Delgado, MM and DiVincenti, LJ and Fujita, K and Herrmann, E and Hiramatsu, C and Jacobs, LF and Jordan, KE and Laude, JR and Leimgruber,
             KL and Messer, EJE and Moura, ACDA and Ostojić, L and Picard, A and Platt,
             ML and Plotnik, JM and Range, F and Reader, SM and Reddy, RB and Sandel,
             AA and Santos, LR and Schumann, K and Seed, AM and Sewall, KB and Shaw, RC and Slocombe, KE and Su, Y and Takimoto, A and Tan, J and Tao, R and van
             Schaik, CP and Virányi, Z and Visalberghi, E and Wade, JC and Watanabe,
             A and Widness, J and Young, JK and Zentall, TR and Zhao,
             Y},
   Title = {The evolution of self-control.},
   Journal = {Proc Natl Acad Sci U S A},
   Volume = {111},
   Number = {20},
   Pages = {E2140-E2148},
   Year = {2014},
   Month = {May},
   ISSN = {0027-8424},
   Abstract = {Cognition presents evolutionary research with one of its
             greatest challenges. Cognitive evolution has been explained
             at the proximate level by shifts in absolute and relative
             brain volume and at the ultimate level by differences in
             social and dietary complexity. However, no study has
             integrated the experimental and phylogenetic approach at the
             scale required to rigorously test these explanations.
             Instead, previous research has largely relied on various
             measures of brain size as proxies for cognitive abilities.
             We experimentally evaluated these major evolutionary
             explanations by quantitatively comparing the cognitive
             performance of 567 individuals representing 36 species on
             two problem-solving tasks measuring self-control.
             Phylogenetic analysis revealed that absolute brain volume
             best predicted performance across species and accounted for
             considerably more variance than brain volume controlling for
             body mass. This result corroborates recent advances in
             evolutionary neurobiology and illustrates the cognitive
             consequences of cortical reorganization through increases in
             brain volume. Within primates, dietary breadth but not
             social group size was a strong predictor of species
             differences in self-control. Our results implicate robust
             evolutionary relationships between dietary breadth, absolute
             brain volume, and self-control. These findings provide a
             significant first step toward quantifying the primate
             cognitive phenome and explaining the process of cognitive
             evolution.},
   Doi = {10.1073/pnas.1323533111},
   Key = {fds240371}
}

@article{fds240377,
   Author = {Bray, J and Krupenye, C and Hare, B},
   Title = {Ring-tailed lemurs (Lemur catta) exploit information about
             what others can see but not what they can
             hear.},
   Journal = {Animal cognition},
   Volume = {17},
   Number = {3},
   Pages = {735-744},
   Year = {2014},
   Month = {May},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/24218121},
   Abstract = {Studies suggest that haplorhine primates are sensitive to
             what others can see and hear. Using two experimental
             designs, we tested the hypothesis that ring-tailed lemurs (N
             = 16) are also sensitive to the visual and auditory
             perception of others. In the first task, we used a go/no-go
             design that required lemurs to exploit only auditory
             information. In the second task, we used a forced-choice
             design where lemurs competed against a human who would
             prevent them from obtaining food if their approaches were
             detected. Subjects were given the choice of obtaining food
             silently or noisily when the competitor's back was turned.
             They were also given the choice to obtain food when the
             competitor could either see them or not. Here, we replicate
             the findings of previous studies indicating that ring-tailed
             lemurs are sensitive to whether they can be seen; however,
             we found no evidence that subjects are sensitive to whether
             others can hear them. Our findings suggest that ring-tailed
             lemurs converge with haplorhine primates only in their
             sensitivity to the visual information of others. The results
             emphasize the importance of investigating social cognition
             across sensory domains in order to elucidate the cognitive
             mechanisms that underlie apparently complex social behavior.
             These findings also suggest that the social dynamics of
             haplorhine groups impose greater cognitive demands than
             lemur groups, despite similarities in total group
             size.},
   Doi = {10.1007/s10071-013-0705-0},
   Key = {fds240377}
}

@article{fds240380,
   Author = {Wobber, V and Herrmann, E and Hare, B and Wrangham, R and Tomasello,
             M},
   Title = {Differences in the early cognitive development of children
             and great apes.},
   Journal = {Developmental psychobiology},
   Volume = {56},
   Number = {3},
   Pages = {547-573},
   Year = {2014},
   Month = {April},
   ISSN = {0012-1630},
   Abstract = {There is very little research comparing great ape and human
             cognition developmentally. In the current studies we
             compared a cross-sectional sample of 2- to 4-year-old human
             children (n=48) with a large sample of chimpanzees and
             bonobos in the same age range (n=42, hereafter: apes) on a
             broad array of cognitive tasks. We then followed a group of
             juvenile apes (n=44) longitudinally over 3 years to track
             their cognitive development in greater detail. In skills of
             physical cognition (space, causality, quantities), children
             and apes performed comparably at 2 years of age, but by 4
             years of age children were more advanced (whereas apes
             stayed at their 2-year-old performance levels). In skills of
             social cognition (communication, social learning, theory of
             mind), children out-performed apes already at 2 years, and
             increased this difference even more by 4 years. Patterns of
             development differed more between children and apes in the
             social domain than the physical domain, with support for
             these patterns present in both the cross-sectional and
             longitudinal ape data sets. These results indicate key
             differences in the pattern and pace of cognitive development
             between humans and other apes, particularly in the early
             emergence of specific social cognitive capacities in
             humans.},
   Doi = {10.1002/dev.21125},
   Key = {fds240380}
}

@article{fds240368,
   Author = {Cieri, RL and Churchill, SE and Franciscus, RG and Tan, J and Hare,
             B},
   Title = {Craniofacial feminization, social tolerance, and the origins
             of behavioral modernity},
   Journal = {Current Anthropology},
   Volume = {55},
   Number = {4},
   Pages = {419-443},
   Publisher = {University of Chicago Press},
   Year = {2014},
   Month = {January},
   ISSN = {0011-3204},
   Abstract = {The past 200,000 years of human cultural evolution have
             witnessed the persistent establishment of behaviors
             involving innovation, planning depth, and abstract and
             symbolic thought, or what has been called "behavioral
             modernity." Demographic models based on increased human
             population density from the late Pleistocene onward have
             been increasingly invoked to understand the emergence of
             behavioral modernity. However, high levels of social
             tolerance, as seen among living humans, are a necessary
             prerequisite to life at higher population densities and to
             the kinds of cooperative cultural behaviors essential to
             these demographic models. Here we provide data on
             craniofacial feminization (reduction in average brow ridge
             projection and shortening of the upper facial skeleton) in
             Homo sapiens from the Middle Pleistocene to recent times. We
             argue that temporal changes in human craniofacial morphology
             reflect reductions in average androgen reactivity (lower
             levels of adult circulating testosterone or reduced androgen
             receptor densities), which in turn reflect the evolution of
             enhanced social tolerance since the Middle Pleistocene. ©
             2014 by The Wenner-Gren Foundation for Anthropological
             Research. All rights reserved.},
   Doi = {10.1086/677209},
   Key = {fds240368}
}

@article{fds240372,
   Author = {Pontzer, H and Raichlen, DA and Gordon, AD and Schroepfer-Walker, KK and Hare, B and O'Neill, MC and Muldoon, KM and Dunsworth, HM and Wood, BM and Isler, K and Burkart, J and Irwin, M and Shumaker, RW and Lonsdorf, EV and Ross, SR},
   Title = {Primate energy expenditure and life history.},
   Journal = {Proceedings of the National Academy of Sciences of the
             United States of America},
   Volume = {111},
   Number = {4},
   Pages = {1433-1437},
   Year = {2014},
   Month = {January},
   ISSN = {0027-8424},
   Abstract = {Humans and other primates are distinct among placental
             mammals in having exceptionally slow rates of growth,
             reproduction, and aging. Primates' slow life history
             schedules are generally thought to reflect an evolved
             strategy of allocating energy away from growth and
             reproduction and toward somatic investment, particularly to
             the development and maintenance of large brains. Here we
             examine an alternative explanation: that primates' slow life
             histories reflect low total energy expenditure (TEE)
             (kilocalories per day) relative to other placental mammals.
             We compared doubly labeled water measurements of TEE among
             17 primate species with similar measures for other placental
             mammals. We found that primates use remarkably little energy
             each day, expending on average only 50% of the energy
             expected for a placental mammal of similar mass. Such large
             differences in TEE are not easily explained by differences
             in physical activity, and instead appear to reflect systemic
             metabolic adaptation for low energy expenditures in
             primates. Indeed, comparisons of wild and captive primate
             populations indicate similar levels of energy expenditure.
             Broad interspecific comparisons of growth, reproduction, and
             maximum life span indicate that primates' slow metabolic
             rates contribute to their characteristically slow life
             histories.},
   Doi = {10.1073/pnas.1316940111},
   Key = {fds240372}
}

@misc{fds330815,
   Author = {Hare, B},
   Title = {Is human free will prisoner to primate, ape, and hominin
             preferences and biases?},
   Pages = {361-366},
   Booktitle = {Moral Psychology, Volume 4: Free Will And Moral
             Responsibility},
   Year = {2014},
   Month = {January},
   ISBN = {9780262525473},
   Key = {fds330815}
}

@article{fds240378,
   Author = {MacLean, E and Hare, B},
   Title = {Spontaneous triadic engagement in bonobos (Pan paniscus) and
             chimpanzees (Pan troglodytes).},
   Journal = {Journal of comparative psychology (Washington, D.C. :
             1983)},
   Volume = {127},
   Number = {3},
   Pages = {245-255},
   Year = {2013},
   Month = {August},
   ISSN = {0735-7036},
   url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000323579000003&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
   Abstract = {Humans are believed to have evolved a unique motivation to
             participate in joint activities that first develops during
             infancy and supports the development of shared
             intentionality. We conducted five experiments with bonobos
             (Pan paniscus) and chimpanzees (Pan troglodytes) (Total n =
             119) to assess their motivation to spontaneously participate
             in joint activities with a conspecific or a human. We found
             that even the youngest subjects preferred to interact
             together with a human and a toy rather than engaging in an
             identical game alone. In addition, we found that subjects
             could spontaneously interact with a human in a turn-taking
             game involving passing a ball back and forth and used
             behaviors to elicit additional interaction when the game was
             disrupted. However, when paired with a conspecific, subjects
             preferred to interact with an object individually rather
             than together. Our results indicate that nonhuman apes are
             motivated to engage in triadic activities if they occur
             spontaneously with humans and require a minimum amount of
             coordination. These findings leave open the question of
             whether these activities are coordinated through shared
             intentions.},
   Doi = {10.1037/a0030935},
   Key = {fds240378}
}

@article{fds240383,
   Author = {Wobber, V and Hare, B and Lipson, S and Wrangham, R and Ellison,
             P},
   Title = {Different ontogenetic patterns of testosterone production
             reflect divergent male reproductive strategies in
             chimpanzees and bonobos.},
   Journal = {Physiology & behavior},
   Volume = {116-117},
   Pages = {44-53},
   Year = {2013},
   Month = {May},
   ISSN = {0031-9384},
   Abstract = {Male reproductive effort is often strongly related to levels
             of the steroid hormone testosterone. However, little
             research has examined whether levels of testosterone
             throughout development might be tied to individual or
             species differences in the reproductive strategies pursued
             by adult males. Here, we tested the hypothesis that
             inter-specific differences in male reproductive strategy are
             associated with differences in the pattern of testosterone
             production throughout early life and puberty. We compared
             testosterone levels from infancy to adulthood in two closely
             related species where levels of mating competition and
             male-male aggression differ significantly, bonobos (Pan
             paniscus) and chimpanzees (Pan troglodytes). We predicted
             that the reduction in male mating competition found in
             bonobos would be accompanied by a lesser developmental
             increase in testosterone production. We performed
             radioimmunoassay of salivary testosterone levels in a
             mixed-longitudinal sample of both species, collected from
             individuals living in semi free-ranging populations. This
             allowed us to examine the effects of development in a more
             naturalistic setting than possible in a zoo or laboratory.
             We found that among chimpanzees, testosterone levels
             declined slightly from infancy to juvenility, then remained
             low until increasing markedly during adolescence (with
             pubertal increases most pronounced among males). In
             contrast, there was little change in testosterone production
             with age in bonobos of either sex, with levels of
             testosterone consistent throughout infancy, juvenility, and
             the transition to adulthood. Our data are therefore
             consistent with the hypothesis that the ontogenetic pattern
             of testosterone production can be subject to rapid
             evolutionary change, shifting in association with species
             differences in male reproductive strategy.},
   Doi = {10.1016/j.physbeh.2013.03.003},
   Key = {fds240383}
}

@article{fds240386,
   Author = {Herrmann, E and Keupp, S and Hare, B and Vaish, A and Tomasello,
             M},
   Title = {Direct and indirect reputation formation in nonhuman great
             apes (Pan paniscus, Pan troglodytes, Gorilla gorilla, Pongo
             pygmaeus) and human children (Homo sapiens).},
   Journal = {Journal of comparative psychology (Washington, D.C. :
             1983)},
   Volume = {127},
   Number = {1},
   Pages = {63-75},
   Year = {2013},
   Month = {February},
   ISSN = {0735-7036},
   url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000315340300010&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
   Abstract = {Humans make decisions about when and with whom to cooperate
             based on their reputations. People either learn about others
             by direct interaction or by observing third-party
             interactions or gossip. An important question is whether
             other animal species, especially our closest living
             relatives, the nonhuman great apes, also form reputations of
             others. In Study 1, chimpanzees, bonobos, orangutans, and
             2.5-year-old human children experienced a nice experimenter
             who tried to give food/toys to the subject and a mean
             experimenter who interrupted the food/toy giving. In studies
             2 and 3, nonhuman great apes and human children could only
             passively observe a similar interaction, in which a nice
             experimenter and a mean experimenter interacted with a third
             party. Orangutans and 2.5-year-old human children preferred
             to approach the nice experimenter rather than the mean one
             after having directly experienced their respective
             behaviors. Orangutans, chimpanzees, and 2.5-year-old human
             children also took into account experimenter actions toward
             third parties in forming reputations. These studies show
             that the human ability to form direct and indirect
             reputation judgment is already present in young children and
             shared with at least some of the other great
             apes.},
   Doi = {10.1037/a0028929},
   Key = {fds240386}
}

@article{fds240379,
   Author = {Maclean, EL and Sandel, AA and Bray, J and Oldenkamp, RE and Reddy, RB and Hare, BA},
   Title = {Group Size Predicts Social but Not Nonsocial Cognition in
             Lemurs.},
   Journal = {PloS one},
   Volume = {8},
   Number = {6},
   Pages = {e66359},
   Booktitle = {PLoS One},
   Year = {2013},
   Month = {January},
   ISSN = {1932-6203},
   Abstract = {The social intelligence hypothesis suggests that living in
             large social networks was the primary selective pressure for
             the evolution of complex cognition in primates. This
             hypothesis is supported by comparative studies demonstrating
             a positive relationship between social group size and
             relative brain size across primates. However, the
             relationship between brain size and cognition remains
             equivocal. Moreover, there have been no experimental studies
             directly testing the association between group size and
             cognition across primates. We tested the social intelligence
             hypothesis by comparing 6 primate species (total N = 96)
             characterized by different group sizes on two cognitive
             tasks. Here, we show that a species' typical social group
             size predicts performance on cognitive measures of social
             cognition, but not a nonsocial measure of inhibitory
             control. We also show that a species' mean brain size (in
             absolute or relative terms) does not predict performance on
             either task in these species. These data provide evidence
             for a relationship between group size and social cognition
             in primates, and reveal the potential for cognitive
             evolution without concomitant changes in brain size.
             Furthermore our results underscore the need for more
             empirical studies of animal cognition, which have the power
             to reveal species differences in cognition not detectable by
             proxy variables, such as brain size.},
   Doi = {10.1371/journal.pone.0066359},
   Key = {fds240379}
}

@article{fds240384,
   Author = {Rosati, AG and Hare, B},
   Title = {Chimpanzees and bonobos exhibit emotional responses to
             decision outcomes.},
   Journal = {PloS one},
   Volume = {8},
   Number = {5},
   Pages = {e63058},
   Year = {2013},
   Month = {January},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/23734175},
   Abstract = {The interface between cognition, emotion, and motivation is
             thought to be of central importance in understanding complex
             cognitive functions such as decision-making and executive
             control in humans. Although nonhuman apes have complex
             repertoires of emotional expression, little is known about
             the role of affective processes in ape decision-making. To
             illuminate the evolutionary origins of human-like patterns
             of choice, we investigated decision-making in humans'
             closest phylogenetic relatives, chimpanzees (Pan
             troglodytes) and bonobos (Pan paniscus). In two studies, we
             examined these species' temporal and risk preferences, and
             assessed whether apes show emotional and motivational
             responses in decision-making contexts. We find that (1)
             chimpanzees are more patient and more risk-prone than are
             bonobos, (2) both species exhibit affective and motivational
             responses following the outcomes of their decisions, and (3)
             some emotional and motivational responses map onto
             species-level and individual-differences in decision-making.
             These results indicate that apes do exhibit emotional
             responses to decision-making, like humans. We explore the
             hypothesis that affective and motivational biases may
             underlie the psychological mechanisms supporting value-based
             preferences in these species.},
   Doi = {10.1371/journal.pone.0063058},
   Key = {fds240384}
}

@article{fds240387,
   Author = {Hare, B},
   Title = {Animal behavior. For $60, a peek inside your dog's
             mind.},
   Journal = {Science (New York, N.Y.)},
   Volume = {339},
   Number = {6117},
   Pages = {260-261},
   Year = {2013},
   Month = {January},
   ISSN = {0036-8075},
   url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000313622000013&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=47d3190e77e5a3a53558812f597b0b92},
   Doi = {10.1126/science.339.6117.260},
   Key = {fds240387}
}

@article{fds240388,
   Author = {Tan, J and Hare, B},
   Title = {Bonobos share with strangers.},
   Journal = {PloS one},
   Volume = {8},
   Number = {1},
   Pages = {e51922},
   Year = {2013},
   Month = {January},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/23300956},
   Abstract = {Humans are thought to possess a unique proclivity to share
             with others--including strangers. This puzzling phenomenon
             has led many to suggest that sharing with strangers
             originates from human-unique language, social norms, warfare
             and/or cooperative breeding. However, bonobos, our closest
             living relative, are highly tolerant and, in the wild, are
             capable of having affiliative interactions with strangers.
             In four experiments, we therefore examined whether bonobos
             will voluntarily donate food to strangers. We show that
             bonobos will forego their own food for the benefit of
             interacting with a stranger. Their prosociality is in part
             driven by unselfish motivation, because bonobos will even
             help strangers acquire out-of-reach food when no desirable
             social interaction is possible. However, this prosociality
             has its limitations because bonobos will not donate food in
             their possession when a social interaction is not possible.
             These results indicate that other-regarding preferences
             toward strangers are not uniquely human. Moreover, language,
             social norms, warfare and cooperative breeding are
             unnecessary for the evolution of xenophilic sharing.
             Instead, we propose that prosociality toward strangers
             initially evolves due to selection for social tolerance,
             allowing the expansion of individual social networks. Human
             social norms and language may subsequently extend this
             ape-like social preference to the most costly
             contexts.},
   Doi = {10.1371/journal.pone.0051922},
   Key = {fds240388}
}

@misc{fds219184,
   Author = {A. Melis and F. Warneken and B. Hare},
   Title = {Collaboration and helping in chimpanzees.},
   Pages = {166-183},
   Booktitle = {The Chimpanzee Mind},
   Year = {2013},
   Key = {fds219184}
}

@article{fds219188,
   Author = {E. Herrmann and B. Hare and J. Cisseski and M. Tomasello},
   Title = {The origins of human temperament: children avoid novelty
             more than other apes.},
   Journal = {Developmental Science},
   Volume = {14},
   Pages = {1393-1405},
   Year = {2013},
   Key = {fds219188}
}

@article{fds219196,
   Author = {E. Herrmann and S. Keupp and B. Hare and A. Vaish and M.
             Tomasello},
   Title = {Direct and indirect reputation formation in great apes and
             human children.},
   Journal = {Journal of Comparative Psychology},
   Volume = {127},
   Pages = {63-75},
   Year = {2013},
   Key = {fds219196}
}

@article{fds219197,
   Author = {E. Maclean and B. Hare},
   Title = {Spontaneous triadic play in bonobos and chimpanzees.},
   Journal = {Journal of Comparative Psychology},
   Year = {2013},
   Key = {fds219197}
}

@article{fds219201,
   Author = {A. Rosati and V. Wobber and F. Warneken and A. Melis and E. Herrmann and J.
             Kaminski, J. Tan and C. Krupenye and K. Schroepfer and B.
             Hare},
   Title = {Assessing the psychological health of cpative and wild apes:
             a response to Ferdowsian et al. in press},
   Journal = {Journal of Comparative Psychology},
   Year = {2013},
   Key = {fds219201}
}

@misc{fds219205,
   Author = {V. Wobber and B. Hare},
   Title = {The evolution of human socio-cognitive development.},
   Booktitle = {The Development of Social Cognition},
   Year = {2013},
   Key = {fds219205}
}

@article{fds219990,
   Author = {T. Wobber and E. Herrmann and B. Hare and R. Wrangham and M.
             Tomasello},
   Title = {The evolution of cognitive development in Pan and
             Homo.},
   Booktitle = {Developmental Psychobiology},
   Year = {2013},
   Key = {fds219990}
}

@book{fds219139,
   Author = {B. Hare and V. Woods},
   Title = {The Genius of Dogs},
   Publisher = {Dutton: Penguin Group},
   Year = {2013},
   Key = {fds219139}
}

@article{fds240385,
   Author = {Bray, EE and MacLean, EL and Hare, BA},
   Title = {Context specificity of inhibitory control in
             dogs},
   Journal = {Animal Cognition},
   Volume = {17},
   Number = {1},
   Pages = {1-17},
   Booktitle = {Animal Cognition},
   Publisher = {Springer Nature},
   Year = {2013},
   ISSN = {1435-9448},
   Abstract = {Across three experiments, we explored whether a dog's
             capacity for inhibitory control is stable or variable across
             decision-making contexts. In the social task, dogs were
             first exposed to the reputations of a stingy experimenter
             that never shared food and a generous experimenter who
             always shared food. In subsequent test trials, dogs were
             required to avoid approaching the stingy experimenter when
             this individual offered (but withheld) a higher-value reward
             than the generous experimenter did. In the A-not-B task,
             dogs were required to inhibit searching for food in a
             previously rewarded location after witnessing the food being
             moved from this location to a novel hiding place. In the
             cylinder task, dogs were required to resist approaching
             visible food directly (because it was behind a transparent
             barrier), in favor of a detour reaching response. Overall,
             dogs exhibited inhibitory control in all three tasks.
             However, individual scores were not correlated between
             tasks, suggesting that context has a large effect on dogs'
             behavior. This result mirrors studies of humans, which have
             highlighted intra-individual variation in inhibitory control
             as a function of the decision-making context. Lastly, we
             observed a correlation between a subject's age and
             performance on the cylinder task, corroborating previous
             observations of age-related decline in dogs' executive
             function.},
   Doi = {10.1007/s10071-013-0633-z},
   Key = {fds240385}
}

@article{fds240444,
   Author = {Nunn, CL and Hare, B},
   Title = {Pathogen flow: what we need to know.},
   Journal = {American journal of primatology},
   Volume = {74},
   Number = {12},
   Pages = {1084-1087},
   Year = {2012},
   Month = {December},
   ISSN = {0275-2565},
   Doi = {10.1002/ajp.22070},
   Key = {fds240444}
}

@article{fds240443,
   Author = {Rosati, AG and Hare, B},
   Title = {Chimpanzees and bonobos exhibit divergent spatial memory
             development.},
   Journal = {Developmental science},
   Volume = {15},
   Number = {6},
   Pages = {840-853},
   Year = {2012},
   Month = {November},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/23106738},
   Abstract = {Spatial cognition and memory are critical cognitive skills
             underlying foraging behaviors for all primates. While the
             emergence of these skills has been the focus of much
             research on human children, little is known about
             ontogenetic patterns shaping spatial cognition in other
             species. Comparative developmental studies of nonhuman apes
             can illuminate which aspects of human spatial development
             are shared with other primates, versus which aspects are
             unique to our lineage. Here we present three studies
             examining spatial memory development in our closest living
             relatives, chimpanzees (Pan troglodytes) and bonobos (P.
             paniscus). We first compared memory in a naturalistic
             foraging task where apes had to recall the location of
             resources hidden in a large outdoor enclosure with a variety
             of landmarks (Studies 1 and 2). We then compared older apes
             using a matched memory choice paradigm (Study 3). We found
             that chimpanzees exhibited more accurate spatial memory than
             bonobos across contexts, supporting predictions from these
             species' different feeding ecologies. Furthermore,
             chimpanzees - but not bonobos - showed developmental
             improvements in spatial memory, indicating that bonobos
             exhibit cognitive paedomorphism (delays in developmental
             timing) in their spatial abilities relative to chimpanzees.
             Together, these results indicate that the development of
             spatial memory may differ even between closely related
             species. Moreover, changes in the spatial domain can emerge
             during nonhuman ape ontogeny, much like some changes seen in
             human children.},
   Doi = {10.1111/j.1467-7687.2012.01182.x},
   Key = {fds240443}
}

@article{fds240442,
   Author = {Rosati, AG and Hare, B},
   Title = {Decision making across social contexts: Competition
             increases preferences for risk in chimpanzees and
             bonobos},
   Journal = {Animal Behaviour},
   Volume = {84},
   Number = {4},
   Pages = {869-879},
   Publisher = {Elsevier BV},
   Year = {2012},
   Month = {October},
   ISSN = {0003-3472},
   url = {http://hdl.handle.net/10161/6945 Duke open access
             repository},
   Abstract = {Context can have a powerful influence on decision-making
             strategies in humans. In particular, people sometimes shift
             their economic preferences depending on the broader social
             context, such as the presence of potential competitors or
             mating partners. Despite the important role of competition
             in primate conspecific interactions, as well as evidence
             that competitive social contexts impact primates' social
             cognitive skills, there has been little study of how social
             context influences the strategies that nonhumans show when
             making decisions about the value of resources. Here we
             investigate the impact of social context on preferences for
             risk (variability in payoffs) in our two closest
             phylogenetic relatives, chimpanzees, Pan troglodytes, and
             bonobos, Pan paniscus. In a first study, we examine the
             impact of competition on patterns of risky choice. In a
             second study, we examine whether a positive play context
             affects risky choices. We find that (1) apes are more likely
             to choose the risky option when making decisions in a
             competitive context; and (2) the play context did not
             influence their risk preferences. Overall these results
             suggest that some types of social contexts can shift
             patterns of decision making in nonhuman apes, much like in
             humans. Comparative studies of chimpanzees and bonobos can
             therefore help illuminate the evolutionary processes shaping
             human economic behaviour. © 2012 The Association for the
             Study of Animal Behaviour.},
   Doi = {10.1016/j.anbehav.2012.07.010},
   Key = {fds240442}
}

@misc{fds240381,
   Author = {Rosati, Alexandra G. and Santos, Laurie R. and Hare,
             B},
   Title = {Primate Neuroethology},
   Pages = {117-143},
   Booktitle = {Primate Neuroethology},
   Publisher = {Oxford University Press, USA},
   Editor = {Platt, ML and Ghazanfar, AA},
   Year = {2012},
   Month = {August},
   ISBN = {9780199929245},
   url = {http://hdl.handle.net/10161/7465 Duke open access
             repository},
   Abstract = {This edited volume is the first of its kind to bridge the
             epistemological gap between primate ethologists and primate
             neurobiologists.},
   Key = {fds240381}
}

@article{fds240441,
   Author = {Hare, B and Wobber, V and Wrangham, R},
   Title = {The self-domestication hypothesis: Evolution of bonobo
             psychology is due to selection against aggression},
   Journal = {Animal Behaviour},
   Volume = {83},
   Number = {3},
   Pages = {573-585},
   Publisher = {Elsevier BV},
   Year = {2012},
   Month = {March},
   ISSN = {0003-3472},
   Abstract = {Experiments indicate that selection against aggression in
             mammals can have multiple effects on their morphology,
             physiology, behaviour and psychology, and that these results
             resemble a syndrome of changes observed in domestic animals.
             We hypothesize that selection against aggression in some
             wild species can operate in a similar way. Here we consider
             the bonobo, Pan paniscus, as a candidate for having
             experienced this 'self-domestication' process. We first
             detail the changes typically seen in domesticated species
             including shifts in development. We then show that bonobos
             show less severe forms of aggression than chimpanzees, Pan
             troglodytes, and suggest that this difference evolved
             because of relaxed feeding competition. We next review
             evidence that phenotypic differences in morphology and
             behaviour between bonobos and chimpanzees are analogous to
             differences between domesticates and their wild ancestors.
             We then synthesize the first set of a priori experimental
             tests of the self-domestication hypothesis comparing the
             psychology of bonobos and chimpanzees. Again, bonobo traits
             echo those of domesticates, including juvenilized patterns
             of development. We conclude that the self-domestication
             hypothesis provides a plausible account of the origin of
             numerous differences between bonobos and chimpanzees, and
             note that many of these appear to have arisen as incidental
             by-products rather than adaptations. These results raise the
             possibility that self-domestication has been a widespread
             process in mammalian evolution, and suggest the need for
             research into the regulatory genes responsible for shifts in
             developmental trajectories in species that have undergone
             selection against aggression. © 2011 The Association for
             the Study of Animal Behaviour.},
   Doi = {10.1016/j.anbehav.2011.12.007},
   Key = {fds240441}
}

@article{fds240446,
   Author = {MacLean, EL and Matthews, LJ and Hare, BA and Nunn, CL and Anderson, RC and Aureli, F and Brannon, EM and Call, J and Drea, CM and Emery, NJ and Haun,
             DBM and Herrmann, E and Jacobs, LF and Platt, ML and Rosati, AG and Sandel,
             AA and Schroepfer, KK and Seed, AM and Tan, J and van Schaik, CP and Wobber, V},
   Title = {How does cognition evolve? Phylogenetic comparative
             psychology.},
   Journal = {Anim Cogn},
   Volume = {15},
   Number = {2},
   Pages = {223-238},
   Year = {2012},
   Month = {March},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/21927850},
   Abstract = {Now more than ever animal studies have the potential to test
             hypotheses regarding how cognition evolves. Comparative
             psychologists have developed new techniques to probe the
             cognitive mechanisms underlying animal behavior, and they
             have become increasingly skillful at adapting methodologies
             to test multiple species. Meanwhile, evolutionary biologists
             have generated quantitative approaches to investigate the
             phylogenetic distribution and function of phenotypic traits,
             including cognition. In particular, phylogenetic methods can
             quantitatively (1) test whether specific cognitive abilities
             are correlated with life history (e.g., lifespan),
             morphology (e.g., brain size), or socio-ecological variables
             (e.g., social system), (2) measure how strongly phylogenetic
             relatedness predicts the distribution of cognitive skills
             across species, and (3) estimate the ancestral state of a
             given cognitive trait using measures of cognitive
             performance from extant species. Phylogenetic methods can
             also be used to guide the selection of species comparisons
             that offer the strongest tests of a priori predictions of
             cognitive evolutionary hypotheses (i.e., phylogenetic
             targeting). Here, we explain how an integration of
             comparative psychology and evolutionary biology will answer
             a host of questions regarding the phylogenetic distribution
             and history of cognitive traits, as well as the evolutionary
             processes that drove their evolution.},
   Doi = {10.1007/s10071-011-0448-8},
   Key = {fds240446}
}

@article{fds240440,
   Author = {MacLean, EL and Hare, B},
   Title = {Bonobos and chimpanzees infer the target of another's
             attention},
   Journal = {Animal Behaviour},
   Volume = {83},
   Number = {2},
   Pages = {345-353},
   Publisher = {Elsevier BV},
   Year = {2012},
   Month = {February},
   ISSN = {0003-3472},
   Abstract = {We examined the ability of bonobos, Pan paniscus (N= 39),
             and chimpanzees, Pan troglodytes (N= 74), to infer the
             target of an experimenter's visual attention in a series of
             three experiments. In each experiment subjects were first
             introduced to a novel object while an experimenter's (E1)
             visual access to this object was manipulated by (1) having
             E1 orient towards or away from the object, (2) positioning a
             visual occluder that did or did not block E1's view of the
             object, or (3) substituting a different experimenter for E1
             during the introduction phase of the trial. After subjects
             were introduced to the objects in one of these ways, E1
             vocalized excitedly while gazing ambiguously towards the
             previously introduced target object and a second location on
             the same visual plane. In each experiment we measured
             whether subjects looked at the object or the alternative
             target of the E1's gaze. We predicted that if subjects
             recognized when E1 was previously familiar with the object,
             they would search for an alternative target of his attention
             more frequently in these trials. In all three contexts,
             chimpanzees, and in one context, bonobos, behaved
             consistently with this prediction. These results are not
             easily explained by learning or behaviour-reading hypotheses
             because responses were never rewarded, few trials were
             conducted per subject, and the experimenter's behaviour was
             the same across experimental conditions at the moment
             subjects were required to respond. Therefore, similar to
             human infants, subjects most likely remembered what the
             experimenter had or had not seen in the past, allowing them
             to infer the target of his attention in the present. © 2011
             The Association for the Study of Animal Behaviour.},
   Doi = {10.1016/j.anbehav.2011.10.026},
   Key = {fds240440}
}

@article{fds219191,
   Author = {E. MacLean and B. Hare},
   Title = {Bonobos and chimpanzees infer the target of an actor's
             attention.},
   Journal = {Animal Behavior},
   Volume = {83},
   Pages = {345-353},
   Year = {2012},
   Key = {fds219191}
}

@article{fds219192,
   Author = {B. Hare and T. Wobber and R. Wrangham},
   Title = {The self-domestication hypothesis: bonobo psychology evolved
             due to selection against male aggression.},
   Journal = {Animal Behavior},
   Volume = {83},
   Pages = {573-585},
   Year = {2012},
   Key = {fds219192}
}

@article{fds219193,
   Author = {A. Rosati and B. Hare},
   Title = {Decision-making across social contexts: competition
             increases risk-prone choices in chimpanzees and
             bonobos.},
   Journal = {Animal Behavior},
   Volume = {84},
   Pages = {869-879},
   Year = {2012},
   Key = {fds219193}
}

@article{fds240439,
   Author = {Herrmann, E and Hare, B and Cissewski, J and Tomasello,
             M},
   Title = {A comparison of temperament in nonhuman apes and human
             infants.},
   Journal = {Developmental science},
   Volume = {14},
   Number = {6},
   Pages = {1393-1405},
   Year = {2011},
   Month = {November},
   ISSN = {1363-755X},
   Abstract = {The adaptive behavior of primates, including humans, is
             often mediated by temperament. Human behavior likely differs
             from that of other primates in part due to temperament. In
             the current study we compared the reaction of bonobos,
             chimpanzees, orangutans, and 2.5-year-old human infants to
             novel objects and people - as a measure of their
             shyness-boldness, a key temperamental trait. Human children
             at the age of 2.5 years avoided novelty of all kinds far
             more than the other ape species. This response was most
             similar to that seen in bonobos and least like that of
             chimpanzees and orangutans. This comparison represents a
             first step in characterizing the temperamental profiles of
             species in the hominoid clade, and these findings are
             consistent with the hypothesis that human temperament has
             evolved since our lineage diverged from the other apes in
             ways that likely have broad effects on behavior. These
             findings also provide new insights into how species
             differences in ecology may shape differences in
             temperament.},
   Doi = {10.1111/j.1467-7687.2011.01082.x},
   Key = {fds240439}
}

@article{fds240436,
   Author = {Hare, B},
   Title = {From hominoid to hominid mind: What changed and
             why?},
   Journal = {Annual Review of Anthropology},
   Volume = {40},
   Number = {1},
   Pages = {293-309},
   Publisher = {ANNUAL REVIEWS},
   Year = {2011},
   Month = {October},
   ISSN = {0084-6570},
   Abstract = {The living great apes, and in particular members of the
             genus Pan, help test hypotheses regarding the cognitive
             skills of our extinct common ancestor. Research with
             chimpanzees suggests that we share some but not all of our
             abilities to model another's perspective in social
             interactions. Large-scale comparisons among human infants,
             bonobos, chimpanzees, and orangutans on both social and
             physical problem-solving tasks demonstrate that human
             infants are unique for their early emerging social cognitive
             skills, which facilitate participation in cultural
             interactions. Comparisons between bonobos and chimpanzees
             also reveal cognitive differences that are likely due to
             developmental shifts. These comparative studies suggest that
             our species' capabilities to assess the psychological states
             of others are built on those abilities that were present in
             our last common ape ancestor and were derived, in part,
             owing to shifts in cognitive ontogeny that likely account
             for species differences among other apes as well. © 2011 by
             Annual Reviews. All rights reserved.},
   Doi = {10.1146/annurev-anthro-081309-145726},
   Key = {fds240436}
}

@article{fds240438,
   Author = {Sandel, AA and MacLean, EL and Hare, B},
   Title = {Evidence from four lemur species that ringtailed lemur
             social cognition converges with that of haplorhine
             primates},
   Journal = {Animal Behaviour},
   Volume = {81},
   Number = {5},
   Pages = {925-931},
   Publisher = {Elsevier BV},
   Year = {2011},
   Month = {May},
   ISSN = {0003-3472},
   Abstract = {Many haplorhine primates flexibly exploit social cues when
             competing for food. Whether strepsirrhine primates possess
             similar abilities is unknown. To explore the phylogenetic
             origins of such skills among primates, we tested ringtailed
             lemurs, Lemur catta, for their ability to exploit social
             cues while competing for food. We found that in two contexts
             ringtailed lemurs spontaneously approached food out of their
             competitor's view. To assess whether these skills are
             related to the relatively complex social structure seen in
             ringtailed lemurs or shared more broadly across a range of
             strepsirrhines, we then compared ringtailed lemurs to three
             lemur species with less complex societies in the same food
             competition task (N=50 lemurs). Although all species
             skilfully avoided food proximate to a competitor in a
             pretest, only ringtailed lemurs performed above chance in
             the food competition task that required subjects to avoid
             food that an experimenter was facing in favour of one that
             he was not facing. We also compared all four species in a
             noncompetitive gaze-following task. Ringtailed lemurs were
             again the only species that looked up more frequently when
             an experimenter gazed into space than when an experimenter
             gazed forward (although at relatively low frequencies).
             These results are consistent with the hypothesis that
             ringtailed lemurs have undergone convergent social-cognitive
             evolution with haplorhines, possibly as an adaptation for
             living in the largest and most complex social groups among
             strepsirrhines. Results are discussed in terms of lemur
             cognitive evolution as well as the social intelligence
             hypothesis. © 2011 The Association for the Study of Animal
             Behaviour.},
   Doi = {10.1016/j.anbehav.2011.01.020},
   Key = {fds240438}
}

@article{fds240448,
   Author = {B. Hare and Woods, V and Hare, B},
   Title = {Bonobo but not chimpanzee infants use socio-sexual contact
             with peers.},
   Journal = {Primates; journal of primatology},
   Volume = {52},
   Number = {2},
   Pages = {111-116},
   Year = {2011},
   Month = {April},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/21127940},
   Abstract = {Bonobos have been observed to use socio-sexual behavior at
             higher frequency than chimpanzees. Little is known about the
             developmental influences that shape this behavior in
             bonobos. We compared the social sexual behavior of wild-born
             bonobo (n = 8) and chimpanzee (n = 16) infants in an
             experimental feeding test. Subjects of both species were
             orphans of the bushmeat trade living at sanctuaries in peer
             groups. During the experiment, chimpanzee infants never had
             socio-sexual interactions with one another. In contrast,
             bonobo infants had socio-sexual interactions significantly
             more than the chimpanzee infants and more often when food
             was presented. During these socio-sexual interactions,
             bonobo infants did not show a preference for heterosexual
             partners or genital-genital positioning that is reproductive
             in adults (e.g. a dorso-ventral posture). These findings
             suggest that the socio-sexual behavior previously observed
             in various captive and wild bonobos is species-typical.
             Wild-born bonobos originating from a large geographical
             range develop this behavior long before puberty and without
             the need for adults initiating such behavior or acting as
             models for observational learning. Meanwhile, chimpanzee
             infants of the same age with similar rearing history show no
             signs of the same socio-sexual behavior. Results are
             interpreted regarding hypotheses for the evolution of bonobo
             psychology.},
   Doi = {10.1007/s10329-010-0229-z},
   Key = {fds240448}
}

@article{fds240437,
   Author = {Rosati, AG and Hare, B},
   Title = {Chimpanzees and bonobos distinguish between risk and
             ambiguity.},
   Journal = {Biology letters},
   Volume = {7},
   Number = {1},
   Pages = {15-18},
   Year = {2011},
   Month = {February},
   ISSN = {1744-9561},
   url = {http://hdl.handle.net/10161/6948 Duke open access
             repository},
   Abstract = {Although recent research has investigated animal
             decision-making under risk, little is known about how
             animals choose under conditions of ambiguity when they lack
             information about the available alternatives. Many models of
             choice behaviour assume that ambiguity does not impact
             decision-makers, but studies of humans suggest that people
             tend to be more averse to choosing ambiguous options than
             risky options with known probabilities. To illuminate the
             evolutionary roots of human economic behaviour, we examined
             whether our closest living relatives, chimpanzees (Pan
             troglodytes) and bonobos (Pan paniscus), share this bias
             against ambiguity. Apes chose between a certain option that
             reliably provided an intermediately preferred food type, and
             a variable option that could vary in the probability that it
             provided a highly preferred food type. To examine the impact
             of ambiguity on ape decision-making, we interspersed trials
             in which chimpanzees and bonobos had no knowledge about the
             probabilities. Both species avoided the ambiguous option
             compared with their choices for a risky option, indicating
             that ambiguity aversion is shared by humans, bonobos and
             chimpanzees.},
   Doi = {10.1098/rsbl.2010.0927},
   Key = {fds240437}
}

@article{fds240433,
   Author = {Wobber, V and Hare, B},
   Title = {Psychological health of orphan bonobos and chimpanzees in
             African sanctuaries.},
   Journal = {PloS one},
   Volume = {6},
   Number = {6},
   Pages = {e17147},
   Year = {2011},
   Month = {January},
   ISSN = {1932-6203},
   Abstract = {<h4>Background</h4>Facilities across Africa care for apes
             orphaned by the trade for "bushmeat." These facilities,
             called sanctuaries, provide housing for apes such as bonobos
             (Pan paniscus) and chimpanzees (Pan troglodytes) who have
             been illegally taken from the wild and sold as pets.
             Although these circumstances are undoubtedly stressful for
             the apes, most individuals arrive at the sanctuaries as
             infants and are subsequently provided with rich physical and
             social environments that can facilitate the expression of
             species-typical behaviors.<h4>Methods and findings</h4>We
             tested whether bonobo and chimpanzee orphans living in
             sanctuaries show any behavioral, physiological, or cognitive
             abnormalities relative to other individuals in captivity as
             a result of the early-life stress they experience. Orphans
             showed lower levels of aberrant behaviors, similar levels of
             average cortisol, and highly similar performances on a broad
             battery of cognitive tests in comparisons with individuals
             of the same species who were either living at a zoo or were
             reared by their mothers at the sanctuaries.<h4>Conclusion</h4>Taken
             together, these results support the rehabilitation strategy
             used by sanctuaries in the Pan-African Sanctuary Alliance
             (PASA) and suggest that the orphans we examined did not show
             long-term signs of stress as a result of their capture. Our
             findings also show that sanctuary apes are as
             psychologically healthy as apes in other captive settings
             and thus represent a valuable resource for non-invasive
             research.},
   Doi = {10.1371/journal.pone.0017147},
   Key = {fds240433}
}

@article{fds240445,
   Author = {Schroepfer, KK and Rosati, AG and Chartrand, T and Hare,
             B},
   Title = {Use of "entertainment" chimpanzees in commercials distorts
             public perception regarding their conservation
             status.},
   Journal = {PloS one},
   Volume = {6},
   Number = {10},
   Pages = {e26048},
   Year = {2011},
   Month = {January},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/22022503},
   Abstract = {Chimpanzees (Pan troglodytes) are often used in movies,
             commercials and print advertisements with the intention of
             eliciting a humorous response from audiences. The portrayal
             of chimpanzees in unnatural, human-like situations may have
             a negative effect on the public's understanding of their
             endangered status in the wild while making them appear as
             suitable pets. Alternatively, media content that elicits a
             positive emotional response toward chimpanzees may increase
             the public's commitment to chimpanzee conservation. To test
             these competing hypotheses, participants (n = 165)
             watched a series of commercials in an experiment framed as a
             marketing study. Imbedded within the same series of
             commercials was one of three chimpanzee videos. Participants
             either watched 1) a chimpanzee conservation commercial, 2)
             commercials containing "entertainment" chimpanzees or 3)
             control footage of the natural behavior of wild chimpanzees.
             Results from a post-viewing questionnaire reveal that
             participants who watched the conservation message understood
             that chimpanzees were endangered and unsuitable as pets at
             higher levels than those viewing the control footage.
             Meanwhile participants watching commercials with
             entertainment chimpanzees showed a decrease in understanding
             relative to those watching the control footage. In addition,
             when participants were given the opportunity to donate part
             of their earnings from the experiment to a conservation
             charity, donations were least frequent in the group watching
             commercials with entertainment chimpanzees. Control
             questions show that participants did not detect the purpose
             of the study. These results firmly support the hypothesis
             that use of entertainment chimpanzees in the popular media
             negatively distorts the public's perception and hinders
             chimpanzee conservation efforts.},
   Doi = {10.1371/journal.pone.0026048},
   Key = {fds240445}
}

@misc{fds219187,
   Author = {B. Hare and J. Tan},
   Title = {What cooperative abilities did we inherit as an
             ape?},
   Booktitle = {The Primate Mind},
   Year = {2011},
   Key = {fds219187}
}

@article{fds202130,
   Author = {B. Hare and A. Sandel and E. Maclean and B. Hare},
   Title = {Convergent evolution in the social cognitive abilities of
             lemurs. Animal Behaviour. 81, 925-931},
   Year = {2011},
   Key = {fds202130}
}

@article{fds202131,
   Author = {B. Hare and T. Wobber and B. Hare},
   Title = {Psychological health of orphan bonobos and chimpanzees in
             African sanctuaries. PLoS One, 6, e17147},
   Year = {2011},
   Key = {fds202131}
}

@article{fds240429,
   Author = {Herrmann, E and Hare, B and Call, J and Tomasello,
             M},
   Title = {Differences in the cognitive skills of bonobos and
             chimpanzees.},
   Journal = {PloS one},
   Volume = {5},
   Number = {8},
   Pages = {e12438},
   Year = {2010},
   Month = {August},
   ISSN = {1932-6203},
   url = {http://hdl.handle.net/10161/4567 Duke open access
             repository},
   Abstract = {While bonobos and chimpanzees are both genetically and
             behaviorally very similar, they also differ in significant
             ways. Bonobos are more cautious and socially tolerant while
             chimpanzees are more dependent on extractive foraging, which
             requires tools. The similarities suggest the two species
             should be cognitively similar while the behavioral
             differences predict where the two species should differ
             cognitively. We compared both species on a wide range of
             cognitive problems testing their understanding of the
             physical and social world. Bonobos were more skilled at
             solving tasks related to theory of mind or an understanding
             of social causality, while chimpanzees were more skilled at
             tasks requiring the use of tools and an understanding of
             physical causality. These species differences support the
             role of ecological and socio-ecological pressures in shaping
             cognitive skills over relatively short periods of
             evolutionary time.},
   Doi = {10.1371/journal.pone.0012438},
   Key = {fds240429}
}

@article{fds240435,
   Author = {Wobber, V and Hare, B and Maboto, J and Lipson, S and Wrangham, R and Ellison, PT},
   Title = {Differential changes in steroid hormones before competition
             in bonobos and chimpanzees.},
   Journal = {Proceedings of the National Academy of Sciences of the
             United States of America},
   Volume = {107},
   Number = {28},
   Pages = {12457-12462},
   Year = {2010},
   Month = {July},
   ISSN = {0027-8424},
   Abstract = {A large body of research has demonstrated that variation in
             competitive behavior across species and individuals is
             linked to variation in physiology. In particular, rapid
             changes in testosterone and cortisol during competition
             differ according to an individual's or species'
             psychological and behavioral responses to competition. This
             suggests that among pairs of species in which there are
             behavioral differences in competition, there should also be
             differences in the endocrine shifts surrounding competition.
             We tested this hypothesis by presenting humans' closest
             living relatives, chimpanzees (Pan troglodytes) and bonobos
             (Pan paniscus), with a dyadic food competition and measuring
             their salivary testosterone and cortisol levels. Given that
             chimpanzees and bonobos differ markedly in their
             food-sharing behavior, we predicted that they would differ
             in their rapid endocrine shifts. We found that in both
             species, males showed an anticipatory decrease (relative to
             baseline) in steroids when placed with a partner in a
             situation in which the two individuals shared food, and an
             anticipatory increase when placed with a partner in a
             situation in which the dominant individual obtained more
             food. The species differed, however, in terms of which
             hormone was affected; in bonobo males the shifts occurred in
             cortisol, whereas in chimpanzee males the shifts occurred in
             testosterone. Thus, in anticipation of an identical
             competition, bonobo and chimpanzee males showed differential
             endocrine shifts, perhaps due to differences in perception
             of the situation, that is, viewing the event either as a
             stressor or a dominance contest. In turn, common selection
             pressures in human evolution may have acted on the
             psychology and the endocrinology of our competitive
             behavior.},
   Doi = {10.1073/pnas.1007411107},
   Key = {fds240435}
}

@misc{fds240382,
   Author = {Rosati, A G and Hare, B},
   Title = {Social Cognition: From Behavior-Reading to
             Mind-Reading},
   Pages = {263-270},
   Booktitle = {Encyclopedia of Behavioral Neuroscience},
   Publisher = {Elsevier Science},
   Editor = {Koob, George F. and Le Moal and Michel},
   Year = {2010},
   Month = {May},
   ISBN = {9780080453965},
   url = {http://hdl.handle.net/10161/7464 Duke open access
             repository},
   Abstract = {Primates must navigate complex social landscapes in their
             daily lives: gathering information from and about others,
             competing with others for rewards like food and mates, and
             cooperating to obtain rewards as well. Although many species
             may exhibit similar behaviors in naturalistic contexts, the
             cognitive bases of the sophisticated behaviors that many
             primates exhibit can vary widely across species. In this
             article, we examine the psychology underlying primate social
             behavior in three situations: gaze-following, competing for
             food, and instrumental cooperation. In each of these
             domains, various primate gaze-follow, compete, and cooperate
             with great success - but experiments have revealed that the
             ways they do so can be quite diverse. These examples provide
             a framework for investigating social cognition from an
             evolutionary perspective that addresses why such different
             social-cognitive skills evolved across species.},
   Doi = {10.1016/B978-0-08-045396-5.00112-3},
   Key = {fds240382}
}

@article{fds240432,
   Author = {Vlamings, PHJM and Hare, B and Call, J},
   Title = {Reaching around barriers: the performance of the great apes
             and 3-5-year-old children.},
   Journal = {Animal cognition},
   Volume = {13},
   Number = {2},
   Pages = {273-285},
   Year = {2010},
   Month = {March},
   ISSN = {1435-9448},
   Abstract = {Inhibitory control has been suggested as a key predictive
             measure of problem-solving skills in human and nonhuman
             animals. However, there has yet to be a direct comparison of
             the inhibitory skills of the nonhuman apes and their
             development in human children. We compared the inhibitory
             skills of all great ape species, including 3-5-year-old
             children in a detour-reaching task, which required subjects
             to avoid reaching directly for food and instead use an
             indirect reaching method to successfully obtain the food. We
             tested 22 chimpanzees, 18 bonobos, 18 orangutans, 6 gorillas
             and 42 children. Our sample included chimpanzees, bonobos
             and orangutans housed in zoos (N = 27) and others housed in
             sanctuaries in their native habitats (N = 37). Overall,
             orangutans were the most skilful apes, including human
             children. As expected older children outperformed younger
             children. Sanctuary chimpanzees and bonobos outperformed
             their zoo counterparts whereas there was no difference
             between the two orangutan samples. Most zoo chimpanzees and
             bonobos failed to solve the original task, but improved
             their performance with additional training, although the
             training method determined to a considerable extent the
             level of success that the apes achieved in a transfer phase.
             In general, the performance of the older children was far
             from perfect and comparable to some of the nonhuman apes
             tested.},
   Doi = {10.1007/s10071-009-0265-5},
   Key = {fds240432}
}

@article{fds240434,
   Author = {Hare, B and Kwetuenda, S},
   Title = {Bonobos voluntarily share their own food with
             others.},
   Journal = {Current biology : CB},
   Volume = {20},
   Number = {5},
   Pages = {R230-R231},
   Year = {2010},
   Month = {March},
   ISSN = {0960-9822},
   Abstract = {Comparisons between chimpanzees and humans have led to the
             hypothesis that only humans voluntarily share their own food
             with others. However, it is hard to draw conclusions because
             the food-sharing preferences of our more tolerant relative,
             the bonobo (Pan paniscus), have never been studied
             experimentally. We gave unrelated bonobos the choice of
             either monopolizing food or actively sharing: we found that
             bonobos preferred to release a recipient from an adjacent
             room and feed together instead of eating all the food alone.
             Thus, food sharing in bonobos does not depend on kinship or
             harassment and suggests our own species' propensity for
             voluntary food sharing is not unique among the
             apes.},
   Doi = {10.1016/j.cub.2009.12.038},
   Key = {fds240434}
}

@misc{fds240366,
   Author = {Rosati, AG and Santos, LR and Hare, B},
   Title = {Primate Social Cognition: Thirty Years After Premack and
             Woodruff},
   Pages = {117-143},
   Booktitle = {Primate Neuroethology},
   Publisher = {Oxford University Press},
   Year = {2010},
   Month = {February},
   ISBN = {9780195326598},
   Abstract = {This chapter addresses two aspects of primate social
             cognition-understanding of intentional, goal-directed
             action, and understanding perceptions, knowledge, and
             beliefs-focusing on the newest comparative research since
             the last major reviews were written on the topic over a
             decade ago. It first reviews evidence suggesting that
             diverse species of primates understand the actions of others
             in terms of goals and intentions, and furthermore can reason
             about some, but probably not all, kinds of psychological
             states. It then examines the hypothesis that primates show
             their most complex social skills in competitive contexts,
             and suggests that inquiry into other aspects of primate
             social life, such as cooperative interactions, may prove to
             be the next important step for experimental inquiries into
             primate social-cognitive skills. Finally, the chapter
             examines primate social cognition in a broader evolutionary
             context that may provide a better understanding of both
             primate and human cognitive skills.},
   Doi = {10.1093/acprof:oso/9780195326598.003.0007},
   Key = {fds240366}
}

@article{fds240431,
   Author = {Wobber, V and Wrangham, R and Hare, B},
   Title = {Bonobos exhibit delayed development of social behavior and
             cognition relative to chimpanzees.},
   Journal = {Current biology : CB},
   Volume = {20},
   Number = {3},
   Pages = {226-230},
   Year = {2010},
   Month = {February},
   ISSN = {0960-9822},
   Abstract = {Phenotypic changes between species can occur when evolution
             shapes development. Here, we tested whether differences in
             the social behavior and cognition of bonobos and chimpanzees
             derive from shifts in their ontogeny, looking at behaviors
             pertaining to feeding competition in particular. We found
             that as chimpanzees (n = 30) reached adulthood, they became
             increasingly intolerant of sharing food, whereas adult
             bonobos (n = 24) maintained high, juvenile levels of
             food-related tolerance. We also investigated the ontogeny of
             inhibition during tasks that simulated feeding competition.
             In two different tests, we found that bonobos (n = 30)
             exhibited developmental delays relative to chimpanzees (n =
             29) in the acquisition of social inhibition, with these
             differences resulting in less skill among adult bonobos. The
             results suggest that these social and cognitive differences
             between two closely related species result from evolutionary
             changes in brain development.},
   Doi = {10.1016/j.cub.2009.11.070},
   Key = {fds240431}
}

@article{fds240428,
   Author = {Herrmann, E and Hernández-Lloreda, MV and Call, J and Hare, B and Tomasello, M},
   Title = {The structure of individual differences in the cognitive
             abilities of children and chimpanzees.},
   Journal = {Psychological science},
   Volume = {21},
   Number = {1},
   Pages = {102-110},
   Year = {2010},
   Month = {January},
   ISSN = {0956-7976},
   Abstract = {Most studies of animal cognition focus on group performance
             and neglect individual differences and the correlational
             structure of cognitive abilities. Moreover, no previous
             studies have compared the correlational structure of
             cognitive abilities in nonhuman animals and humans. We
             compared the structure of individual differences of 106
             chimpanzees and 105 two-year-old human children using 15
             cognitive tasks that posed problems about the physical or
             social world. We found a similar factor of spatial cognition
             for the two species. But whereas the chimpanzees had only a
             single factor in addition to spatial cognition, the children
             had two distinct additional factors: one for physical
             cognition and one for social cognition. These findings, in
             combination with previous research, support the proposal
             that humans share many cognitive skills with nonhuman apes,
             especially for dealing with the physical world, but in
             addition have evolved some specialized skills of social
             cognition.},
   Doi = {10.1177/0956797609356511},
   Key = {fds240428}
}

@misc{fds375266,
   Author = {Rosati, AG and Hare, B},
   Title = {Social Cognition: From Behavior-Reading to
             Mind-Reading},
   Volume = {3},
   Pages = {V3-263-V3-268},
   Booktitle = {Encyclopedia of Behavioral Neuroscience, Three-Volume Set,
             1-3},
   Year = {2010},
   Month = {January},
   ISBN = {9780080914558},
   Abstract = {Primates must navigate complex social landscapes in their
             daily lives: gathering information from and about others,
             competing with others for rewards like food and mates, and
             cooperating to obtain rewards as well. Although many species
             may exhibit similar behaviors in naturalistic contexts, the
             cognitive bases of the sophisticated behaviors that many
             primates exhibit can vary widely across species. In this
             article, we examine the psychology underlying primate social
             behavior in three situations: gaze-following, competing for
             food, and instrumental cooperation. In each of these
             domains, various primate gaze-follow, compete, and cooperate
             with great success – but experiments have revealed that
             the ways they do so can be quite diverse. These examples
             provide a framework for investigating social cognition from
             an evolutionary perspective that addresses why such
             different social-cognitive skills evolved across
             species.},
   Doi = {10.1016/B978-0-08-045396-5.00112-3},
   Key = {fds375266}
}

@article{fds219173,
   Author = {B. Hare and B. Rosati and A. Breaur and J. Kaminski and J. Call and M.
             Tomasello},
   Title = {Dogs are more skilled than wolves with human social cues: a
             response to Udell et al (2008) and Wynne et
             al.},
   Journal = {Animal Behavior},
   Volume = {79},
   Pages = {e1-e6},
   Year = {2010},
   Key = {fds219173}
}

@article{fds219179,
   Author = {V. Wobber and R. Wrangham and B. Hare},
   Title = {Application of the heterochrony framework to the study of
             behavior and cognition.},
   Journal = {Communicative and Integrative Biology},
   Volume = {3},
   Pages = {1-2},
   Year = {2010},
   Key = {fds219179}
}

@misc{fds219182,
   Author = {V. Woods and B. Hare},
   Title = {African sanctuaries as a new resource for non-invasive
             research on great apes.},
   Booktitle = {Encyclopedia of Applied Animal Behavior and
             Welfare},
   Year = {2010},
   Key = {fds219182}
}

@misc{fds219183,
   Author = {A. Rosati and B. Hare},
   Title = {From social behavior to social cognition in
             primates.},
   Booktitle = {Encyclopedia of Behavioral Neuroscience},
   Year = {2010},
   Key = {fds219183}
}

@article{fds219185,
   Author = {A. Rosati and B. Hare},
   Title = {Chimpanzee and bonobos distinguish between risk and
             ambiguity.},
   Journal = {Proceedings of Royal Society: Biology Letters.},
   Volume = {7},
   Pages = {15-18},
   Year = {2010},
   Key = {fds219185}
}

@article{fds240430,
   Author = {Hare, B and Rosati, AG and Kaminski, J and Braeuer, J and Call, J and Tomasello, M},
   Title = {The domestication hypothesis for dogs' skills with human
             communication: A response to Udell et al. (2008) and Wynne
             et al. (2008)},
   Journal = {Animal Behaviour},
   Volume = {79},
   Number = {2},
   Pages = {e1-e6},
   Publisher = {Elsevier BV},
   Year = {2010},
   ISSN = {0003-3472},
   url = {http://hdl.handle.net/10161/6631 Duke open access
             repository},
   Doi = {10.1016/j.anbehav.2009.06.031},
   Key = {fds240430}
}

@article{fds240427,
   Author = {Melis, AP and Hare, B and Tomasello, M},
   Title = {Chimpanzees coordinate in a negotiation game},
   Journal = {Evolution and Human Behavior},
   Volume = {30},
   Number = {6},
   Pages = {381-392},
   Publisher = {Elsevier BV},
   Year = {2009},
   Month = {November},
   ISSN = {1090-5138},
   Abstract = {A crucially important aspect of human cooperation is the
             ability to negotiate to cooperative outcomes when interests
             over resources conflict. Although chimpanzees and other
             social species may negotiate conflicting interests regarding
             travel direction or activity timing, very little is known
             about their ability to negotiate conflicting preferences
             over food. In the current study, we presented pairs of
             chimpanzees with a choice between two cooperative tasks-one
             with equal payoffs (e.g., 5-5) and one with unequal payoffs
             (higher and lower than in the equal option, e.g., 10-1).
             This created a conflict of interests between partners with
             failure to work together on the same cooperative task
             resulting in no payoff for either partner. The chimpanzee
             pairs cooperated successfully in as many as 78-94% of the
             trials across experiments. Even though dominant chimpanzees
             preferred the unequal option (as they would obtain the
             largest payoff), subordinate chimpanzees were able to get
             their way (the equal option) in 22-56% of trials across
             conditions. Various analyses showed that subjects were both
             strategic and also cognizant of the strategies used by their
             partners. These results demonstrate that one of our two
             closest primate relatives, the chimpanzee, can settle
             conflicts of interest over resources in mutually satisfying
             ways-even without the social norms of equity, planned
             strategies of reciprocity, and the complex communication
             characteristic of human negotiation. © 2009 Elsevier Inc.
             All rights reserved.},
   Doi = {10.1016/j.evolhumbehav.2009.05.003},
   Key = {fds240427}
}

@article{fds240423,
   Author = {Wobber, V and Hare, B and Koler-Matznick, J and Wrangham, R and Tomasello, M},
   Title = {Breed differences in domestic dogs' (Canis familiaris)
             comprehension of human communicative signals},
   Journal = {Interaction Studies},
   Volume = {10},
   Number = {2},
   Pages = {206-224},
   Publisher = {John Benjamins Publishing Company},
   Editor = {Matsuzawa, T},
   Year = {2009},
   Month = {September},
   ISSN = {1572-0373},
   Abstract = {Recent research suggests that some human-like social skills
             evolved in dogs (Canis familiaris) during domestication as
             an incidental by-product of selection for "tame" forms of
             behavior. It is still possible, however, that the social
             skills of certain dog breeds came under direct selection
             that led to further increases in social problem solving
             ability. To test this hypothesis, different breeds of
             domestic dogs were compared for their ability to use various
             human communicative behaviors to find hidden food. We found
             that even primitive breeds with little human contact were
             able to use communicative cues. Further, "working" dogs
             (shepherds and huskies: thought to be bred intentionally to
             respond to human cooperative communicative signals) were
             more skilled at using gestural cues than were non-working
             breeds (basenji and toy poodles: not thought to have been
             bred for their cooperative-communicative ability). This
             difference in performance existed regardless of whether the
             working breeds were more or less genetically wolf-like.
             These results suggest that subsequent to initial
             domesticating selection giving rise to cue-following skills,
             additional selection on communicative abilities in certain
             breeds has produced substantive differences in those breeds'
             abilities to follow cues. © John Benjamins Publishing
             Company.},
   Doi = {10.1075/is.10.2.06wob},
   Key = {fds240423}
}

@article{fds240426,
   Author = {Wobber, V and Hare, B},
   Title = {Testing the social dog hypothesis: are dogs also more
             skilled than chimpanzees in non-communicative social
             tasks?},
   Journal = {Behavioural processes},
   Volume = {81},
   Number = {3},
   Pages = {423-428},
   Year = {2009},
   Month = {July},
   ISSN = {0376-6357},
   Abstract = {Relative to non-human primates, domestic dogs possess a
             number of social skills that seem exceptional-particularly
             in solving problems involving cooperation and communication
             with humans. However, the degree to which dogs' unusual
             skills are contextually specialized is still unclear. Here,
             we presented dogs with a social problem that did not require
             them to use cooperative-communicative cues and compared
             their performance to that of chimpanzees to assess the
             extent of dogs' capabilities relative to those of non-human
             primates. We tested the abilities of dogs and chimpanzees to
             inhibit previously learned responses by using a social and a
             non-social version of a reversal learning task. In contrast
             to previous findings in cooperative-communicative social
             tasks, dogs were not more skilled on the social task than
             the non-social task, while chimpanzees were significantly
             better in the social paradigm. Chimpanzees were able to
             inhibit their prior learning better and more quickly in the
             social paradigm than they were in the non-social paradigm,
             while dogs took more time to inhibit what they had learned
             in both versions of the task. These results suggest that the
             dogs' sophisticated social skills in using human social cues
             may be relatively specialized as a result of
             domestication.},
   Doi = {10.1016/j.beproc.2009.04.003},
   Key = {fds240426}
}

@article{fds240425,
   Author = {McIntyre, MH and Herrmann, E and Wobber, V and Halbwax, M and Mohamba,
             C and de Sousa, N and Atencia, R and Cox, D and Hare,
             B},
   Title = {Bonobos have a more human-like second-to-fourth finger
             length ratio (2D:4D) than chimpanzees: a hypothesized
             indication of lower prenatal androgens.},
   Journal = {Journal of human evolution},
   Volume = {56},
   Number = {4},
   Pages = {361-365},
   Year = {2009},
   Month = {April},
   ISSN = {0047-2484},
   Abstract = {The ratio of the second-to-fourth finger lengths (2D:4D) has
             been proposed as an indicator of prenatal sex
             differentiation. However, 2D:4D has not been studied in the
             closest living human relatives, chimpanzees (Pan
             troglodytes) and bonobos (Pan paniscus). We report the
             results from 79 chimpanzees and 39 bonobos of both sexes,
             including infants, juveniles, and adults. We observed the
             expected sex difference in 2D:4D, and substantially higher,
             more human-like, 2D:4D in bonobos than chimpanzees. Previous
             research indicates that sex differences in 2D:4D result from
             differences in prenatal sex hormone levels. We hypothesize
             that the species difference in 2D:4D between bonobos and
             chimpanzees suggests a possible role for early exposure to
             sex hormones in the development of behavioral differences
             between the two species.},
   Doi = {10.1016/j.jhevol.2008.12.004},
   Key = {fds240425}
}

@article{fds240424,
   Author = {Rosati, AG and Hare, B},
   Title = {Looking past the model species: diversity in gaze-following
             skills across primates.},
   Journal = {Current opinion in neurobiology},
   Volume = {19},
   Number = {1},
   Pages = {45-51},
   Year = {2009},
   Month = {February},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/19394214},
   Abstract = {Primates must navigate complex social landscapes in their
             daily lives: gathering information from and about others,
             competing with others for food and mates, and cooperating to
             obtain rewards as well. Gaze-following often provides
             important clues as to what others see, know, or will do;
             using information about social attention is thus crucial for
             primates to be competent social actors. However, the
             cognitive bases of the gaze-following behaviors that
             primates exhibit appear to vary widely across species. The
             ultimate challenge of such analyses will therefore be to
             understand why such different cognitive mechanisms have
             evolved across species.},
   Doi = {10.1016/j.conb.2009.03.002},
   Key = {fds240424}
}

@misc{fds219140,
   Author = {B. Hare},
   Title = {What is the effect of affect on bonobo and chimpanzee
             problem solving?},
   Pages = {89-102},
   Booktitle = {The Neurobiology of the Unwelt: how living beings perceive
             the world.},
   Year = {2009},
   Key = {fds219140}
}

@article{fds219142,
   Author = {A. Rosati and B. Hare},
   Title = {Beyond the model species: diversity in gaze following skills
             across primates.},
   Journal = {Current Opinion in Neurobiology},
   Volume = {19},
   Pages = {45-51},
   Year = {2009},
   Key = {fds219142}
}

@misc{fds219143,
   Author = {B. Hare and V. Woods},
   Title = {Out of our minds: how did Homo sapiens come down from the
             trees, and why did no one follow?},
   Pages = {170-184},
   Booktitle = {Innovative Science},
   Year = {2009},
   Key = {fds219143}
}

@article{fds240421,
   Author = {Wobber, V and Hare, B and Wrangham, R},
   Title = {Great apes prefer cooked food.},
   Journal = {Journal of human evolution},
   Volume = {55},
   Number = {2},
   Pages = {340-348},
   Year = {2008},
   Month = {August},
   ISSN = {0047-2484},
   Abstract = {The cooking hypothesis proposes that a diet of cooked food
             was responsible for diverse morphological and behavioral
             changes in human evolution. However, it does not predict
             whether a preference for cooked food evolved before or after
             the control of fire. This question is important because the
             greater the preference shown by a raw-food-eating hominid
             for the properties present in cooked food, the more easily
             cooking should have been adopted following the control of
             fire. Here we use great apes to model food preferences by
             Paleolithic hominids. We conducted preference tests with
             various plant and animal foods to determine whether great
             apes prefer food items raw or cooked. We found that several
             populations of captive apes tended to prefer their food
             cooked, though with important exceptions. These results
             suggest that Paleolithic hominids would likewise have
             spontaneously preferred cooked food to raw, exapting a
             pre-existing preference for high-quality, easily chewed
             foods onto these cooked items. The results, therefore,
             challenge the hypothesis that the control of fire preceded
             cooking by a significant period.},
   Doi = {10.1016/j.jhevol.2008.03.003},
   Key = {fds240421}
}

@article{fds240419,
   Author = {Heilbronner, SR and Rosati, AG and Stevens, JR and Hare, B and Hauser,
             MD},
   Title = {A fruit in the hand or two in the bush? Divergent risk
             preferences in chimpanzees and bonobos.},
   Journal = {Biology letters},
   Volume = {4},
   Number = {3},
   Pages = {246-249},
   Year = {2008},
   Month = {June},
   ISSN = {1744-9561},
   url = {http://hdl.handle.net/10161/7404 Duke open access
             repository},
   Abstract = {Human and non-human animals tend to avoid risky prospects.
             If such patterns of economic choice are adaptive, risk
             preferences should reflect the typical decision-making
             environments faced by organisms. However, this approach has
             not been widely used to examine the risk sensitivity in
             closely related species with different ecologies. Here, we
             experimentally examined risk-sensitive behaviour in
             chimpanzees (Pan troglodytes) and bonobos (Pan paniscus),
             closely related species whose distinct ecologies are thought
             to be the major selective force shaping their unique
             behavioural repertoires. Because chimpanzees exploit riskier
             food sources in the wild, we predicted that they would
             exhibit greater tolerance for risk in choices about food.
             Results confirmed this prediction: chimpanzees significantly
             preferred the risky option, whereas bonobos preferred the
             fixed option. These results provide a relatively rare
             example of risk-prone behaviour in the context of gains and
             show how ecological pressures can sculpt economic decision
             making.},
   Doi = {10.1098/rsbl.2008.0081},
   Key = {fds240419}
}

@article{fds240420,
   Author = {Ross, SR and Lukas, KE and Lonsdorf, EV and Stoinski, TS and Hare, B and Shumaker, R and Goodall, J},
   Title = {Science priorities. Inappropriate use and portrayal of
             chimpanzees.},
   Journal = {Science (New York, N.Y.)},
   Volume = {319},
   Number = {5869},
   Pages = {1487},
   Year = {2008},
   Month = {March},
   ISSN = {0036-8075},
   Abstract = {Depictions of chimpanzees as caricatures can lead people to
             think these animals are not endangered and is a problem for
             conservation and welfare efforts.},
   Doi = {10.1126/science.1154490},
   Key = {fds240420}
}

@article{fds240418,
   Author = {Herrmann, E and Call, J and Hernández-Lloreda, MV and Hare, B and Tomasello, M},
   Title = {Response [3]},
   Journal = {Science},
   Volume = {319},
   Number = {5863},
   Pages = {569},
   Year = {2008},
   Month = {February},
   ISSN = {0036-8075},
   Key = {fds240418}
}

@article{fds240422,
   Author = {Melis, AP and Hare, B and Tomasello, M},
   Title = {Do chimpanzees reciprocate received favours?},
   Journal = {Animal Behaviour},
   Volume = {76},
   Number = {3},
   Pages = {951-962},
   Publisher = {Elsevier BV},
   Year = {2008},
   Month = {January},
   ISSN = {0003-3472},
   Abstract = {Reciprocal interactions observed in animals may persist
             because individuals keep careful account of services
             exchanged with each group member. To test whether
             chimpanzees, Pan troglodytes, possess the cognitive skills
             required for this type of contingency-based reciprocity, we
             gave chimpanzees the choice of cooperating with a
             conspecific who had helped them previously or one who had
             not helped them in two different experimental tasks. In the
             first experiment, one of the partners preferentially
             recruited the subjects to cooperate in a mutualistic task,
             while the other potential partner never chose to cooperate
             with the subject, but rather chose a different partner. In
             the second experiment, one of the partners altruistically
             helped the subjects to reach food, while the other partner
             never helped the subject, but rather took the food himself.
             In both experiments there was some evidence that the
             chimpanzees increased the amount they cooperated with or
             helped the partner who had been more helpful towards them
             compared to their baseline behaviour towards the same
             individual (or in a control condition). However, in both
             experiments this effect was relatively weak and subjects did
             not preferentially favour the individual who had favoured
             them over the one who had not in either experiment. Although
             taken together, these experiments provide some support for
             the hypothesis that chimpanzees are capable of contingent
             reciprocity, they also suggest that models of immediate
             reciprocation and detailed accounts of recent exchanges
             (e.g. Tit for Tat) may not play a large role in guiding the
             social decisions of chimpanzees. © 2008 The Association for
             the Study of Animal Behaviour.},
   Doi = {10.1016/j.anbehav.2008.05.014},
   Key = {fds240422}
}

@article{fds240417,
   Author = {Rosati, AG and Stevens, JR and Hare, B and Hauser,
             MD},
   Title = {The evolutionary origins of human patience: temporal
             preferences in chimpanzees, bonobos, and human
             adults.},
   Journal = {Current biology : CB},
   Volume = {17},
   Number = {19},
   Pages = {1663-1668},
   Year = {2007},
   Month = {October},
   ISSN = {0960-9822},
   url = {http://www.ncbi.nlm.nih.gov/pubmed/17900899},
   Abstract = {To make adaptive choices, individuals must sometimes exhibit
             patience, forgoing immediate benefits to acquire more
             valuable future rewards [1-3]. Although humans account for
             future consequences when making temporal decisions [4], many
             animal species wait only a few seconds for delayed benefits
             [5-10]. Current research thus suggests a phylogenetic gap
             between patient humans and impulsive, present-oriented
             animals [9, 11], a distinction with implications for our
             understanding of economic decision making [12] and the
             origins of human cooperation [13]. On the basis of a series
             of experimental results, we reject this conclusion. First,
             bonobos (Pan paniscus) and chimpanzees (Pan troglodytes)
             exhibit a degree of patience not seen in other animals
             tested thus far. Second, humans are less willing to wait for
             food rewards than are chimpanzees. Third, humans are more
             willing to wait for monetary rewards than for food, and show
             the highest degree of patience only in response to decisions
             about money involving low opportunity costs. These findings
             suggest that core components of the capacity for
             future-oriented decisions evolved before the human lineage
             diverged from apes. Moreover, the different levels of
             patience that humans exhibit might be driven by fundamental
             differences in the mechanisms representing biological versus
             abstract rewards.},
   Doi = {10.1016/j.cub.2007.08.033},
   Key = {fds240417}
}

@article{fds240415,
   Author = {Herrmann, E and Call, J and Hernàndez-Lloreda, MV and Hare, B and Tomasello, M},
   Title = {Humans have evolved specialized skills of social cognition:
             the cultural intelligence hypothesis.},
   Journal = {Science (New York, N.Y.)},
   Volume = {317},
   Number = {5843},
   Pages = {1360-1366},
   Year = {2007},
   Month = {September},
   ISSN = {0036-8075},
   Abstract = {Humans have many cognitive skills not possessed by their
             nearest primate relatives. The cultural intelligence
             hypothesis argues that this is mainly due to a
             species-specific set of social-cognitive skills, emerging
             early in ontogeny, for participating and exchanging
             knowledge in cultural groups. We tested this hypothesis by
             giving a comprehensive battery of cognitive tests to large
             numbers of two of humans' closest primate relatives,
             chimpanzees and orangutans, as well as to 2.5-year-old human
             children before literacy and schooling. Supporting the
             cultural intelligence hypothesis and contradicting the
             hypothesis that humans simply have more "general
             intelligence," we found that the children and chimpanzees
             had very similar cognitive skills for dealing with the
             physical world but that the children had more sophisticated
             cognitive skills than either of the ape species for dealing
             with the social world.},
   Doi = {10.1126/science.1146282},
   Key = {fds240415}
}

@article{fds240416,
   Author = {Warneken, F and Hare, B and Melis, AP and Hanus, D and Tomasello,
             M},
   Title = {Spontaneous altruism by chimpanzees and young
             children.},
   Journal = {PLoS biology},
   Volume = {5},
   Number = {7},
   Pages = {e184},
   Year = {2007},
   Month = {July},
   ISSN = {1545-7885},
   Abstract = {People often act on behalf of others. They do so without
             immediate personal gain, at cost to themselves, and even
             toward unfamiliar individuals. Many researchers have claimed
             that such altruism emanates from a species-unique psychology
             not found in humans' closest living evolutionary relatives,
             such as the chimpanzee. In favor of this view, the few
             experimental studies on altruism in chimpanzees have
             produced mostly negative results. In contrast, we report
             experimental evidence that chimpanzees perform basic forms
             of helping in the absence of rewards spontaneously and
             repeatedly toward humans and conspecifics. In two
             comparative studies, semi-free ranging chimpanzees helped an
             unfamiliar human to the same degree as did human infants,
             irrespective of being rewarded (experiment 1) or whether the
             helping was costly (experiment 2). In a third study,
             chimpanzees helped an unrelated conspecific gain access to
             food in a novel situation that required subjects to use a
             newly acquired skill on behalf of another individual. These
             results indicate that chimpanzees share crucial aspects of
             altruism with humans, suggesting that the roots of human
             altruism may go deeper than previous experimental evidence
             suggested.},
   Doi = {10.1371/journal.pbio.0050184},
   Key = {fds240416}
}

@article{fds240414,
   Author = {Burnham, TC and Hare, B},
   Title = {Engineering human cooperation : DDDDDoes involuntary neural
             activation increase public goods contributions?},
   Journal = {Human Nature},
   Volume = {18},
   Number = {2},
   Pages = {88-108},
   Publisher = {Springer Nature},
   Year = {2007},
   Month = {June},
   ISSN = {1045-6767},
   Abstract = {In a laboratory experiment, we use a public goods game to
             examine the hypothesis that human subjects use an
             involuntary eye-detector mechanism for evaluating the level
             of privacy. Half of our subjects are "watched" by images of
             a robot presented on their computer screen. The robot-named
             Kismet and invented at MIT-is constructed from objects that
             are obviously not human with the exception of its eyes. In
             our experiment, Kismet produces a significant difference in
             behavior that is not consistent with existing economic
             models of preferences, either self- or other-regarding.
             Subjects who are "watched" by Kismet contribute 29% more to
             the public good than do subjects in the same setting without
             Kismet. © 2007 Springer Science & Business Media,
             LLC.},
   Doi = {10.1007/s12110-007-9012-2},
   Key = {fds240414}
}

@article{fds240411,
   Author = {Hare, B and Melis, AP and Woods, V and Hastings, S and Wrangham,
             R},
   Title = {Tolerance allows bonobos to outperform chimpanzees on a
             cooperative task.},
   Journal = {Current biology : CB},
   Volume = {17},
   Number = {7},
   Pages = {619-623},
   Year = {2007},
   Month = {April},
   ISSN = {0960-9822},
   Abstract = {To understand constraints on the evolution of cooperation,
             we compared the ability of bonobos and chimpanzees to
             cooperatively solve a food-retrieval problem. We addressed
             two hypotheses. The "emotional-reactivity hypothesis"
             predicts that bonobos will cooperate more successfully
             because tolerance levels are higher in bonobos. This
             prediction is inspired by studies of domesticated animals;
             such studies suggest that selection on emotional reactivity
             can influence the ability to solve social problems [1, 2].
             In contrast, the "hunting hypothesis" predicts that
             chimpanzees will cooperate more successfully because only
             chimpanzees have been reported to cooperatively hunt in the
             wild [3-5]. We indexed emotional reactivity by measuring
             social tolerance while the animals were cofeeding and found
             that bonobos were more tolerant of cofeeding than
             chimpanzees. In addition, during cofeeding tests only
             bonobos exhibited socio-sexual behavior, and they played
             more. When presented with a task of retrieving food that was
             difficult to monopolize, bonobos and chimpanzees were
             equally cooperative. However, when the food reward was
             highly monopolizable, bonobos were more successful than
             chimpanzees at cooperating to retrieve it. These results
             support the emotional-reactivity hypothesis. Selection on
             temperament may in part explain the variance in cooperative
             ability across species, including hominoids.},
   Doi = {10.1016/j.cub.2007.02.040},
   Key = {fds240411}
}

@article{fds240412,
   Author = {Hare, B},
   Title = {From nonhuman to human mind: What changed and
             why?},
   Journal = {Current Directions in Psychological Science},
   Volume = {16},
   Number = {2},
   Pages = {60-64},
   Publisher = {SAGE Publications},
   Year = {2007},
   Month = {April},
   ISSN = {0963-7214},
   Abstract = {Two questions regarding the human mind challenge
             evolutionary theory: (a) What features of human psychology
             have changed since humans' lineage split from that of the
             other apes such as chimpanzees and bonobos? And (b) what was
             the process by which such derived psychological features
             evolved (e.g., what were the selection pressures)? I review
             some of the latest research on chimpanzee and canine
             psychology that allows inferences to be made regarding these
             questions. Copyright © 2007 Association for Psychological
             Science.},
   Doi = {10.1111/j.1467-8721.2007.00476.x},
   Key = {fds240412}
}

@article{fds240410,
   Author = {Tomasello, M and Hare, B and Lehmann, H and Call,
             J},
   Title = {Reliance on head versus eyes in the gaze following of great
             apes and human infants: the cooperative eye
             hypothesis.},
   Journal = {Journal of human evolution},
   Volume = {52},
   Number = {3},
   Pages = {314-320},
   Year = {2007},
   Month = {March},
   ISSN = {0047-2484},
   Abstract = {As compared with other primates, humans have especially
             visible eyes (e.g., white sclera). One hypothesis is that
             this feature of human eyes evolved to make it easier for
             conspecifics to follow an individual's gaze direction in
             close-range joint attentional and communicative
             interactions, which would seem to imply especially
             cooperative (mututalistic) conspecifics. In the current
             study, we tested one aspect of this cooperative eye
             hypothesis by comparing the gaze following behavior of great
             apes to that of human infants. A human experimenter "looked"
             to the ceiling either with his eyes only, head only (eyes
             closed), both head and eyes, or neither. Great apes followed
             gaze to the ceiling based mainly on the human's head
             direction (although eye direction played some role as well).
             In contrast, human infants relied almost exclusively on eye
             direction in these same situations. These results
             demonstrate that humans are especially reliant on eyes in
             gaze following situations, and thus, suggest that eyes
             evolved a new social function in human evolution, most
             likely to support cooperative (mututalistic) social
             interactions.},
   Doi = {10.1016/j.jhevol.2006.10.001},
   Key = {fds240410}
}

@article{fds240413,
   Author = {Warneken, F and Hare, B and Melis, AP and Hanus, D and Tomasello,
             M},
   Title = {Spontaneous altruism by chimpanzees and young
             children},
   Journal = {PLoS Biology},
   Volume = {5},
   Number = {7},
   Pages = {1414-1420},
   Year = {2007},
   ISSN = {1544-9173},
   Abstract = {People often act on behalf of others. They do so without
             immediate personal gain, at cost to themselves, and even
             toward unfamiliar individuals. Many researchers have claimed
             that such altruism emanates from a species-unique psychology
             not found in humans' closest living evolutionary relatives,
             such as the chimpanzee. In favor of this view, the few
             experimental studies on altruism in chimpanzees have
             produced mostly negative results. In contrast, we report
             experimental evidence that chimpanzees perform basic forms
             of helping in the absence of rewards spontaneously and
             repeatedly toward humans and conspecifics. In two
             comparative studies, semi-free ranging chimpanzees helped an
             unfamiliar human to the same degree as did human infants,
             irrespective of being rewarded (experiment 1) or whether the
             helping was costly (experiment 2). In a third study,
             chimpanzees helped an unrelated conspecific gain access to
             food in a novel situation that required subjects to use a
             newly acquired skill on behalf of another individual. These
             results indicate that chimpanzees share crucial aspects of
             altruism with humans, suggesting that the roots of human
             altruism may go deeper than previous experimental evidence
             suggested. © 2007 Warneken et al.},
   Doi = {10.1371/journal.pbio.0050184},
   Key = {fds240413}
}

@article{fds240407,
   Author = {Hare, B and Call, J and Tomasello, M},
   Title = {Chimpanzees deceive a human competitor by
             hiding.},
   Journal = {Cognition},
   Volume = {101},
   Number = {3},
   Pages = {495-514},
   Year = {2006},
   Month = {October},
   ISSN = {0010-0277},
   Abstract = {There is little experimental evidence that any non-human
             species is capable of purposefully attempting to manipulate
             the psychological states of others deceptively (e.g.,
             manipulating what another sees). We show here that
             chimpanzees, one of humans' two closest primate relatives,
             sometimes attempt to actively conceal things from others.
             Specifically, when competing with a human in three novel
             tests, eight chimpanzees, from their first trials, chose to
             approach a contested food item via a route hidden from the
             human's view (sometimes using a circuitous path to do so).
             These findings not only corroborate previous work showing
             that chimpanzees know what others can and cannot see, but
             also suggest that when competing for food chimpanzees are
             skillful at manipulating, to their own advantage, whether
             others can or cannot see them.},
   Doi = {10.1016/j.cognition.2005.01.011},
   Key = {fds240407}
}

@article{fds240409,
   Author = {Melis, AP and Hare, B and Tomasello, M},
   Title = {Engineering cooperation in chimpanzees: tolerance
             constraints on cooperation},
   Journal = {Animal Behaviour},
   Volume = {72},
   Number = {2},
   Pages = {275-286},
   Publisher = {Elsevier BV},
   Year = {2006},
   Month = {August},
   ISSN = {0003-3472},
   Abstract = {The cooperative abilities of captive chimpanzees, Pan
             troglodytes, in experiments do not match the sophistication
             that might be predicted based on their naturally occurring
             cooperative behaviours. This discrepancy might partly be
             because in previous experiments potential chimpanzee
             cooperators were partnered without regard to their social
             relationship. We investigated the ability of chimpanzee
             dyads to solve a physical task cooperatively in relation to
             their interindividual tolerance levels. Pairs that were most
             capable of sharing food outside the test were also able to
             cooperate spontaneously (by simultaneously pulling two
             ropes) to obtain food. In contrast, pairs that were less
             inclined to share food outside of the test were unlikely to
             cooperate. Furthermore, previously successful subjects
             stopped cooperating when paired with a less tolerant
             partner, even when the food rewards were presented in a
             dispersed and divisible form to reduce competition between
             subjects. These results show that although chimpanzees are
             capable of spontaneous cooperation in a novel instrumental
             task, tolerance acts as a constraint on their ability to
             solve such cooperative problems. This finding highlights the
             importance of controlling such social constraints in future
             experiments on chimpanzee cooperation, and suggests that the
             evolution of human-like cooperative skills might have been
             preceded by the evolution of a more egalitarian social
             system and a more human-like temperament. © 2006 The
             Association for the Study of Animal Behaviour.},
   Doi = {10.1016/j.anbehav.2005.09.018},
   Key = {fds240409}
}

@article{fds240447,
   Author = {Jensen, K and Hare, B and Call, J and Tomasello, M},
   Title = {What's in it for me? Self-regard precludes altruism and
             spite in chimpanzees.},
   Journal = {Proceedings. Biological sciences},
   Volume = {273},
   Number = {1589},
   Pages = {1013-1021},
   Year = {2006},
   Month = {April},
   ISSN = {0962-8452},
   Abstract = {Sensitivity to fairness may influence whether individuals
             choose to engage in acts that are mutually beneficial,
             selfish, altruistic, or spiteful. In a series of three
             experiments, chimpanzees (Pan troglodytes) could pull a rope
             to access out-of-reach food while concomitantly pulling
             another piece of food further away. In the first study, they
             could make a choice that solely benefited themselves
             (selfishness), or both themselves and another chimpanzee
             (mutualism). In the next two experiments, they could choose
             between providing food solely for another chimpanzee
             (altruism), or for neither while preventing the other
             chimpanzee from receiving a benefit (spite). The main result
             across all studies was that chimpanzees made their choices
             based solely on personal gain, with no regard for the
             outcomes of a conspecific. These results raise questions
             about the origins of human cooperative behaviour.},
   Doi = {10.1098/rspb.2005.3417},
   Key = {fds240447}
}

@article{fds240406,
   Author = {Melis, AP and Hare, B and Tomasello, M},
   Title = {Chimpanzees recruit the best collaborators.},
   Journal = {Science (New York, N.Y.)},
   Volume = {311},
   Number = {5765},
   Pages = {1297-1300},
   Year = {2006},
   Month = {March},
   ISSN = {0036-8075},
   Abstract = {Humans collaborate with non-kin in special ways, but the
             evolutionary foundations of these collaborative skills
             remain unclear. We presented chimpanzees with collaboration
             problems in which they had to decide when to recruit a
             partner and which potential partner to recruit. In an
             initial study, individuals recruited a collaborator only
             when solving the problem required collaboration. In a second
             study, individuals recruited the more effective of two
             partners on the basis of their experience with each of them
             on a previous day. Therefore, recognizing when collaboration
             is necessary and determining who is the best collaborative
             partner are skills shared by both chimpanzees and humans, so
             such skills may have been present in their common ancestor
             before humans evolved their own complex forms of
             collaboration.},
   Doi = {10.1126/science.1123007},
   Key = {fds240406}
}

@article{fds240405,
   Author = {Miklósi, A and Topál, J},
   Title = {Is there a simple recipe for how to make
             friends?},
   Journal = {Trends in cognitive sciences},
   Volume = {9},
   Number = {10},
   Pages = {463-464},
   Year = {2005},
   Month = {October},
   Doi = {10.1016/j.tics.2005.08.009},
   Key = {fds240405}
}

@article{fds240403,
   Author = {Hare, B and Tomasello, M},
   Title = {Human-like social skills in dogs?},
   Journal = {Trends in cognitive sciences},
   Volume = {9},
   Number = {9},
   Pages = {439-444},
   Year = {2005},
   Month = {September},
   ISSN = {1364-6613},
   Abstract = {Domestic dogs are unusually skilled at reading human social
             and communicative behavior--even more so than our nearest
             primate relatives. For example, they use human social and
             communicative behavior (e.g. a pointing gesture) to find
             hidden food, and they know what the human can and cannot see
             in various situations. Recent comparisons between canid
             species suggest that these unusual social skills have a
             heritable component and initially evolved during
             domestication as a result of selection on systems mediating
             fear and aggression towards humans. Differences in
             chimpanzee and human temperament suggest that a similar
             process may have been an important catalyst leading to the
             evolution of unusual social skills in our own species. The
             study of convergent evolution provides an exciting
             opportunity to gain further insights into the evolutionary
             processes leading to human-like forms of cooperation and
             communication.},
   Doi = {10.1016/j.tics.2005.07.003},
   Key = {fds240403}
}

@article{fds240404,
   Author = {Hare, B and Plyusnina, I and Ignacio, N and Schepina, O and Stepika, A and Wrangham, R and Trut, L},
   Title = {Social cognitive evolution in captive foxes is a correlated
             by-product of experimental domestication.},
   Journal = {Current biology : CB},
   Volume = {15},
   Number = {3},
   Pages = {226-230},
   Year = {2005},
   Month = {February},
   ISSN = {0960-9822},
   Abstract = {Dogs have an unusual ability for reading human communicative
             gestures (e.g., pointing) in comparison to either nonhuman
             primates (including chimpanzees) or wolves . Although this
             unusual communicative ability seems to have evolved during
             domestication , it is unclear whether this evolution
             occurred as a result of direct selection for this ability,
             as previously hypothesized , or as a correlated by-product
             of selection against fear and aggression toward humans--as
             is the case with a number of morphological and physiological
             changes associated with domestication . We show here that
             fox kits from an experimental population selectively bred
             over 45 years to approach humans fearlessly and
             nonaggressively (i.e., experimentally domesticated) are not
             only as skillful as dog puppies in using human gestures but
             are also more skilled than fox kits from a second, control
             population not bred for tame behavior (critically, neither
             population of foxes was ever bred or tested for their
             ability to use human gestures) . These results suggest that
             sociocognitive evolution has occurred in the experimental
             foxes, and possibly domestic dogs, as a correlated
             by-product of selection on systems mediating fear and
             aggression, and it is likely the observed social cognitive
             evolution did not require direct selection for improved
             social cognitive ability.},
   Doi = {10.1016/j.cub.2005.01.040},
   Key = {fds240404}
}

@article{fds240401,
   Author = {Hare, B and Tomasello, M},
   Title = {Chimpanzees are more skilful in competitive than in
             cooperative cognitive tasks},
   Journal = {Animal Behaviour},
   Volume = {68},
   Number = {3},
   Pages = {571-581},
   Publisher = {Elsevier BV},
   Year = {2004},
   Month = {September},
   Abstract = {In a series of four experiments, chimpanzees, Pan
             troglodytes, were given two cognitive tasks, an object
             choice task and a discrimination task (based on location),
             each in the context of either cooperation or competition. In
             both tasks chimpanzees performed more skilfully when
             competing than when cooperating, with some evidence that
             competition with conspecifics was especially facilitatory in
             the discrimination location task. This is the first study to
             demonstrate a facilitative cognitive effect for competition
             in a single experimental paradigm. We suggest that
             chimpanzee cognitive evolution is best understood in its
             socioecological context. © 2004 The Association for the
             Study of Animal Behaviour. Published by Elsevier Ltd. All
             rights reserved.},
   Doi = {10.1016/j.anbehav.2003.11.011},
   Key = {fds240401}
}

@article{fds240402,
   Author = {Call, J and Hare, B and Carpenter, M and Tomasello,
             M},
   Title = {'Unwilling' versus 'unable': chimpanzees' understanding of
             human intentional action.},
   Journal = {Developmental science},
   Volume = {7},
   Number = {4},
   Pages = {488-498},
   Year = {2004},
   Month = {September},
   Abstract = {Understanding the intentional actions of others is a
             fundamental part of human social cognition and behavior. An
             important question is therefore whether other animal
             species, especially our nearest relatives the chimpanzees,
             also understand the intentional actions of others. Here we
             show that chimpanzees spontaneously (without training)
             behave differently depending on whether a human is unwilling
             or unable to give them food Chimpanzees produced more
             behaviors and left the testing station earlier with an
             unwilling compared to an unable (but willing) experimenter
             These data together with other recent studies on
             chimpanzees' knowledge about others' visual perception show
             that chimpanzees know more about the intentional actions and
             perceptions of others than previously demonstrated},
   Doi = {10.1111/j.1467-7687.2004.00368.x},
   Key = {fds240402}
}

@article{fds240400,
   Author = {Tomasello, M and Call, J and Hare, B},
   Title = {Chimpanzees versus humans: It's not that
             simple},
   Journal = {Trends in Cognitive Sciences},
   Volume = {7},
   Number = {6},
   Pages = {239-240},
   Publisher = {Elsevier BV},
   Year = {2003},
   Month = {June},
   Doi = {10.1016/S1364-6613(03)00107-4},
   Key = {fds240400}
}

@article{fds240398,
   Author = {Tomasello, M and Call, J and Hare, B},
   Title = {Chimpanzees understand psychological states - The question
             is which ones and to what extent},
   Journal = {Trends in Cognitive Sciences},
   Volume = {7},
   Number = {4},
   Pages = {153-156},
   Publisher = {Elsevier BV},
   Year = {2003},
   Month = {April},
   Abstract = {New data suggest that relatively drastic revisions are
             needed in our theoretical accounts of what other animal
             species understand about the psychological states of others.
             Specifically, chimpanzees seem to understand some things
             about what others do and do not see, or have and have not
             seen in the immediate past, as well as some things about
             others' goal-directed activities. This is especially so in
             competitive situations. They clearly do not have a
             human-like theory of mind, however, and so the challenge is
             to specify precisely how ape and human social cognition are
             similar and different.},
   Doi = {10.1016/S1364-6613(03)00035-4},
   Key = {fds240398}
}

@article{fds240399,
   Author = {Hare, B and Addessi, E and Call, J and Tomasello, M and Visalberghi,
             E},
   Title = {Do capuchin monkeys, Cebus apella, know what conspecifics do
             and do not see?},
   Journal = {Animal Behaviour},
   Volume = {65},
   Number = {1},
   Pages = {131-142},
   Publisher = {Elsevier BV},
   Year = {2003},
   Month = {January},
   Abstract = {Capuchin monkeys were tested in five experiments in which
             two individuals competed over food. When given a choice
             between retrieving a piece of food that was visible or
             hidden from the dominant, subordinate animals preferred to
             retrieve hidden food. This preference is consistent with the
             hypotheses that either (1) the subordinate knew what the
             dominant could and could not see or (2) the subordinate was
             monitoring the behaviour of the dominant and avoiding the
             piece of food that it approached. To test between these
             alternatives, we released subordinates with a slight head
             start forcing them to make their choice (between a piece of
             food hidden or visible to the dominant) before the dominant
             entered the area. Unlike chimpanzees, Pan troglodytes,
             subordinates that were given a head start did not
             preferentially approach hidden pieces of food first.
             Therefore, our experiments provide little support for the
             hypothesis that capuchin monkeys are sensitive to what
             another individual does or does not see. We compare our
             results with those obtained with chimpanzees in the same
             paradigm and discuss the evolution of primate social
             cognition. © 2003 The Association for the Study of Animal
             Behaviour. Published by Elsevier Science Ltd. All rights
             reserved.},
   Doi = {10.1006/anbe.2002.2017},
   Key = {fds240399}
}

@article{fds240395,
   Author = {Hare, B and Brown, M and Williamson, C and Tomasello,
             M},
   Title = {The domestication of social cognition in
             dogs.},
   Journal = {Science (New York, N.Y.)},
   Volume = {298},
   Number = {5598},
   Pages = {1634-1636},
   Year = {2002},
   Month = {November},
   Abstract = {Dogs are more skillful than great apes at a number of tasks
             in which they must read human communicative signals
             indicating the location of hidden food. In this study, we
             found that wolves who were raised by humans do not show
             these same skills, whereas domestic dog puppies only a few
             weeks old, even those that have had little human contact, do
             show these skills. These findings suggest that during the
             process of domestication, dogs have been selected for a set
             of social-cognitive abilities that enable them to
             communicate with humans in unique ways.},
   Doi = {10.1126/science.1072702},
   Key = {fds240395}
}

@article{fds240376,
   Author = {Hare, B},
   Title = {Can competitive paradigms increase the validity of
             experiments on primate social cognition?},
   Journal = {Animal Cognition},
   Volume = {4},
   Number = {3-4},
   Pages = {269-280},
   Publisher = {Springer Nature},
   Year = {2001},
   Month = {December},
   ISSN = {1435-9448},
   Abstract = {Experiments vary in their ability to distinguish between
             competing hypotheses. In tests on primate cognition the
             majority of this variation is due to an experimenter's
             ability to test primates in valid settings while providing
             the adequate amount of experimental control. While
             experimenters studying primate cognition can use methods of
             control perfected in captivity, it is still very unclear how
             to design and then objectively evaluate the external
             validity of new experimental paradigms. I recommend that
             more effort be allocated to specify how to create relevant
             test settings for primates. Primate social life is highly
             competitive. This means that all aspects of primates
             themselves, including their cognitive abilities, have likely
             been shaped by the need to out-compete conspecifics. Based
             on this hypothesis, sophisticated cognitive abilities of
             primates might best be demonstrated in competitive contexts.
             Thus, it is suggested that one possible measure of validity
             is whether investigators integrate a competitive component
             into their experimental designs. To evaluate this
             methodological prediction I review the literature on
             chimpanzee perspective- taking as a case study including
             several recent studies that include a competitive component
             in their experimental designs. © Springer-Verlag
             2001.},
   Doi = {10.1007/s100710100084},
   Key = {fds240376}
}

@article{fds240396,
   Author = {Tomasello, M and Hare, B and Fogleman, T},
   Title = {The ontogeny of gaze following in chimpanzees, Pan
             troglodytes, and rhesus macaques, Macaca
             mulatta},
   Journal = {Animal Behaviour},
   Volume = {61},
   Number = {2},
   Pages = {335-343},
   Publisher = {Elsevier BV},
   Year = {2001},
   Month = {January},
   ISSN = {0003-3472},
   Abstract = {Primates follow the gaze direction of conspecifics to
             outside objects. We followed the ontogeny of this
             social-cognitive skill for two species: rhesus macaques and
             chimpanzees, in the first two experiments, using both a
             cross-sectional and a longitudinal design, we exposed
             individuals of different ages to a human looking in a
             specified direction. Rhesus infants first began reliably to
             follow the direction of this gaze at the end of the early
             infancy period, at about 5.5 months of age. Chimpanzees did
             not reliably follow human gaze until 3-4 years; this
             corresponds to the latter part of the late infancy period
             for this species. In the third experiment we exposed
             individuals of the same two species to a human repeatedly
             looking to the same location (with no special object at that
             location) to see if subjects would learn to ignore the
             looks. Only adults of the two species diminished their
             gaze-following behaviour over trials. This suggests that in
             the period between infancy and adulthood individuals of both
             species come to integrate their gaze-following skills with
             their more general social-cognitive knowledge about other
             animate beings and their behaviour, and so become able to
             deploy their gaze-following skills in a more flexible
             manner. © 2001 The Association for the Study of Animal
             Behaviour.},
   Doi = {10.1006/anbe.2000.1598},
   Key = {fds240396}
}

@article{fds240397,
   Author = {Hare, B and Call, J and Tomasello, M},
   Title = {Do chimpanzees know what conspecifics know?},
   Journal = {Animal Behaviour},
   Volume = {61},
   Number = {1},
   Pages = {139-151},
   Publisher = {Elsevier BV},
   Year = {2001},
   Month = {January},
   ISSN = {0003-3472},
   Abstract = {We conducted three experiments on social problem solving by
             chimpanzees, Pan troglodytes. In each experiment a
             subordinate and a dominant individual competed for food,
             which was placed in various ways on the subordinate's side
             of two opaque barriers. In some conditions dominants had not
             seen the food hidden, or food they had seen hidden was moved
             elsewhere when they were not watching (whereas in control
             conditions they saw the food being hidden or moved). At the
             same time, subordinates always saw the entire baiting
             procedure and could monitor the visual access of their
             dominant competitor as well. If subordinates were sensitive
             to what dominants did or did not see during baiting, they
             should have preferentially approached and retrieved the food
             that dominants had not seen hidden or moved. This is what
             they did in experiment 1 when dominants were either
             uninformed or misinformed about the food's location. In
             experiment 2 subordinates recognized, and adjusted their
             behaviour accordingly, when the dominant individual who
             witnessed the hiding was replaced with another dominant
             individual who had not witnessed it, thus demonstrating
             their ability to keep track of precisely who has witnessed
             what. In experiment 3 subordinates did not choose
             consistently between two pieces of hidden food, one of which
             dominants had seen hidden and one of which they had not seen
             hidden. However, their failure in this experiment was likely
             to be due to the changed nature of the competition under
             these circumstances and not to a failure of social-cognitive
             skills. These findings suggest that at least in some
             situations (i.e. competition with conspecifics) chimpanzees
             know what conspecifics have and have not seen (do and do not
             know), and that they use this information to devise
             effective social-cognitive strategies. © 2001 The
             Association for the Study of Animal Behaviour.},
   Doi = {10.1006/anbe.2000.1518},
   Key = {fds240397}
}

@article{fds240375,
   Author = {Agnetta, B and Hare, B and Tomasello, M},
   Title = {Cues to food location that domestic dogs (Canis familiaris)
             of different ages do and do not use},
   Journal = {Animal Cognition},
   Volume = {3},
   Number = {2},
   Pages = {107-112},
   Publisher = {Springer Nature},
   Year = {2000},
   Month = {December},
   ISSN = {1435-9448},
   Abstract = {The results of three experiments are reported. In the main
             study, a human experimenter presented domestic dogs (Canis
             familiaris) with a variety of social cues intended to
             indicate the location of hidden food. The novel findings of
             this study were: (1) dogs were able to use successfully
             several totally novel cues in which they watched a human
             place a marker in front of the target location; (2) dogs
             were unable to use the marker by itself with no behavioral
             cues (suggesting that some form of human behavior directed
             to the target location was a necessary part of the cue); and
             (3) there were no significant developments in dogs' skills
             in these tasks across the age range 4 months to 4 years
             (arguing against the necessity of extensive learning
             experiences with humans). In a follow- up study, dogs did
             not follow human gaze into "empty space" outside of the
             simulated foraging context. Finally, in a small pilot study,
             two arctic wolves (Canis lupus) were unable to use human
             cues to locate hidden food. These results suggest the
             possibility that domestic dogs have evolved an adaptive
             specialization for using human-produced directional cues in
             a goal-directed (especially foraging) context. Exactly how
             they understand these cues is still an open question. ©
             Springer-Verlag 2000.},
   Doi = {10.1007/s100710000070},
   Key = {fds240375}
}

@article{fds240393,
   Author = {Wrangham, R and Wilson, M and Hare, B and Wolfe, ND},
   Title = {Chimpanzee predation and the ecology of microbial
             exchange},
   Journal = {Microbial Ecology in Health and Disease},
   Volume = {12},
   Number = {3},
   Pages = {186-188},
   Year = {2000},
   Month = {January},
   Abstract = {Hunting provides one mechanism for the transmission of
             microbes across host species boundaries. It has generally
             been assumed that this mechanism leads to unidirectional
             transmission to humans. We report that wild chimpanzees
             occasionally prey on human children. This result and other
             evidence of chimpanzee hunting show the need for
             consideration of more complex predation-mediated host
             networks.},
   Doi = {10.1080/089106000750051855},
   Key = {fds240393}
}

@article{fds240394,
   Author = {Hare, B and Call, J and Agnetta, B and Tomasello,
             M},
   Title = {Chimpanzees know what conspecifics do and do not
             see},
   Journal = {Animal Behaviour},
   Volume = {59},
   Number = {4},
   Pages = {771-785},
   Publisher = {Elsevier BV},
   Year = {2000},
   Month = {January},
   ISSN = {0003-3472},
   Abstract = {We report a series of experiments on social problem solving
             in chimpanzees, Pan troglodytes. In each experiment a
             subordinate and a dominant individual were put into
             competition over two pieces of food. In all experiments
             dominants obtained virtually all of the foods to which they
             had good visual and physical access. However, subordinates
             were successful quite often in three situations in which
             they had better visual access to the food than the dominant,
             for example, when the food was positioned so that only the
             subordinate (and not the dominant) could see it. In some
             cases, the subordinate might have been monitoring the
             behaviour of the dominant directly and simply avoided the
             food that the dominant was moving towards (which just
             happened to be the one it could see). In other cases,
             however, we ruled out this possibility by giving
             subordinates a small headstart and forcing them to make
             their choice (to go to the food that both competitors could
             see, or the food that only they could see) before the
             dominant was released into the area. Together with other
             recent studies, the present investigation suggests that
             chimpanzees know what conspecifics can and cannot see, and,
             furthermore, that they use this knowledge to devise
             effective social-cognitive strategies in naturally occurring
             food competition situations. (C)2000 The Association for the
             Study of Animal Behaviour.},
   Doi = {10.1006/anbe.1999.1377},
   Key = {fds240394}
}

@article{fds240389,
   Author = {Hare, B and Tomasello, M},
   Title = {Domestic dogs (Canis familiaris) use human and conspecific
             social cues to locate hidden food},
   Journal = {Journal of Comparative Psychology},
   Volume = {113},
   Number = {2},
   Pages = {X173-X177},
   Year = {1999},
   Month = {January},
   ISSN = {0735-7036},
   Abstract = {Ten domestic dogs (Canis familiaris) of different breeds and
             ages were exposed to 2 different social cues indicating the
             location of hidden food, each provided by both a human
             informant and a conspecific informant (for a total of 4
             different social cues). For the local enhancement cue the
             informant approached the location where food was hidden and
             then stayed beside it. For the gaze and point cue, the
             informant stood equidistant between 2 hiding locations and
             bodily oriented and gazed toward the 1 in which food was
             hidden (the human informant also pointed). Eight of the 10
             subjects, including the one 6-month-old juvenile, were above
             chance with 2 or more cues. Results are discussed in terms
             of the phylogenetic and ontogenetic processes by means of
             which dogs come to use social cues to locate
             food.},
   Doi = {10.1037//0735-7036.113.2.173},
   Key = {fds240389}
}

@article{fds240391,
   Author = {Itakura, S and Agnetta, B and Hare, B and Tomasello,
             M},
   Title = {Chimpanzee use of human and conspecific social cues to
             locate hidden food},
   Journal = {Developmental Science},
   Volume = {2},
   Number = {4},
   Pages = {448-456},
   Publisher = {WILEY},
   Year = {1999},
   Month = {January},
   Abstract = {Two studies are reported in which chimpanzees attempted to
             use social cues to locate hidden food in one of two possible
             hiding places. In the first study four chimpanzees were
             exposed to a local enhancement cue (the informant approached
             and looked to the location where food was hidden and then
             remained beside it) and a gaze/point cue (the informant
             gazed and manually pointed towards the location where the
             food was hidden). Each cue was given by both a human
             informant and a chimpanzee informant. In the second study 12
             chimpanzees were exposed to a gaze direction cue in
             combination with a vocal cue (the human informant gazed to
             the hiding location and produced one of two different
             vocalizations: a 'food-bark' or a human word-form). The
             results were: (i) all subjects were quite skillful with the
             local enhancement cue, no matter who produced it; (ii) few
             subjects were skillful with the gaze/point cue, no matter
             who produced it (most of these being individuals who had
             been raised in infancy by humans); and (iii) most subjects
             were skillful when the human gazed and vocalized at the
             hiding place, with little difference between the two types
             of vocal cue. Findings are discussed in terms of
             chimpanzees' apparent need for additional cues, over and
             above gaze direction cues, to indicate the presence of
             food.},
   Doi = {10.1111/1467-7687.00089},
   Key = {fds240391}
}

@article{fds240392,
   Author = {Tomasello, M and Hare, B and Agnetta, B},
   Title = {Chimpanzees, Pan troglodytes, follow gaze direction
             geometrically},
   Journal = {Animal Behaviour},
   Volume = {58},
   Number = {4},
   Pages = {769-777},
   Publisher = {Elsevier BV},
   Year = {1999},
   Month = {January},
   ISSN = {0003-3472},
   Abstract = {Two experiments on chimpanzee gaze following are reported.
             In the first, chimpanzee subjects watched as a human
             experimenter looked around various types of barriers. The
             subjects looked around each of the barriers more when the
             human had done so than in a control condition (in which the
             human looked-in another direction). In the second
             experiment, chimpanzees watched as a human looked towards
             the back of their cage. As they turned to follow the human's
             gaze a distractor-object was presented. The chimpanzees
             looked at the distractor while still following the human's
             gaze to the back of the cage. These two experiments
             effectively disconfirm the low-level model of chimpanzee
             gaze following in which it is claimed that upon seeing
             another animate being's gaze direction chimpanzees simply
             turn in that direction and look around for something
             interesting. Rather, they support the hypothesis that
             chimpanzees follow the gaze direction of other animate
             beings geometrically to specific locations, in much the same
             way as human infants. The degree to which chimpanzees have a
             mentalistic interpretation of the gaze and/or visual
             experience of others is still an open question.},
   Doi = {10.1006/anbe.1999.1192},
   Key = {fds240392}
}

@article{fds240390,
   Author = {Tomasello, M and Call, J and Hare, B},
   Title = {Five primate species follow the visual gaze of
             conspecifics},
   Journal = {Animal Behaviour},
   Volume = {55},
   Number = {4},
   Pages = {1063-1069},
   Publisher = {Elsevier BV},
   Year = {1998},
   Month = {January},
   ISSN = {0003-3472},
   Abstract = {Individuals from five primate species were tested
             experimentally for their ability to follow the visual gaze
             of conspecifics to an outside object. Subjects were from
             captive social groups of chimpanzees, Pan troglodytes, sooty
             mangabeys, Cercocebus atys torquatus, rhesus macaques,
             Macaca mulatta, stumptail macaques, M. arctoides, and
             pigtail macaques, M. nemestrina. Experimental trials
             consisted of an experimenter inducing one individual to look
             at food being displayed, and then observing the reaction of
             another individual (the subject) that was looking at that
             individual (not the food). Control trials consisted of an
             experimenter displaying the food in an identical manner when
             the subject was alone. Individuals from all species reliably
             followed the gaze of conspecifics, looking to the food about
             80% of the time in experimental trials, compared with about
             20% of the time in control trials. Results are discussed in
             terms of both the proximate mechanisms that might be
             involved and the adaptive functions that might be served by
             gaze-following.},
   Doi = {10.1006/anbe.1997.0636},
   Key = {fds240390}
}