Faculty Database Psychology and Neuroscience Arts & Sciences Duke University |
||
HOME > Arts & Sciences > pn > Faculty | Search Help Login |
| Publications of Brian Hare :chronological alphabetical combined listing:%% Journal Articles @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}, url = {http://dx.doi.org/10.3758/s13420-023-00576-2}, 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}, url = {http://dx.doi.org/10.1007/s12110-022-09427-x}, 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}, url = {http://dx.doi.org/10.1242/jeb.242218}, 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}, url = {http://dx.doi.org/10.1016/j.cub.2021.06.051}, 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}, url = {http://dx.doi.org/10.1016/j.cub.2021.02.045}, 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}, url = {http://dx.doi.org/10.1007/s10071-020-01443-7}, 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}, url = {http://dx.doi.org/10.1007/s10071-021-01491-7}, 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}, url = {http://dx.doi.org/10.1002/ajp.23217}, 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}, url = {http://dx.doi.org/10.1093/icb/icaa112}, 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}, url = {http://dx.doi.org/10.1007/s10071-020-01400-4}, 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}, url = {http://dx.doi.org/10.1016/j.anbehav.2020.05.019}, 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}, url = {http://dx.doi.org/10.1007/s10071-020-01385-0}, 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}, url = {http://dx.doi.org/10.1371/journal.pone.0230315}, 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}, url = {http://dx.doi.org/10.1163/1568539X-bja10002}, 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} } @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}, url = {http://dx.doi.org/10.1007/s10071-018-01234-1}, 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} } @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}, url = {http://dx.doi.org/10.3389/fpsyg.2019.02955}, 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} } @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}, url = {http://dx.doi.org/10.1111/desc.12598}, 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}, url = {http://dx.doi.org/10.1007/s10818-017-9264-9}, 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}, url = {http://dx.doi.org/10.1016/j.cub.2017.11.061}, 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}, url = {http://dx.doi.org/10.3389/fvets.2018.00236}, 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} } @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}, url = {http://dx.doi.org/10.1038/s41598-017-15320-w}, 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}, url = {http://dx.doi.org/10.1016/j.anbehav.2017.01.005}, 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}, url = {http://dx.doi.org/10.1146/annurev-psych-010416-044201}, 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}, url = {http://dx.doi.org/10.1007/s10071-016-0986-1}, 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}, url = {http://dx.doi.org/10.1038/nature17654}, 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}, url = {http://dx.doi.org/10.1016/j.evolhumbehav.2015.10.003}, 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}, url = {http://dx.doi.org/10.1098/rsbl.2015.0959}, 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}, 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}, 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}, url = {http://dx.doi.org/10.1007/s10329-015-0467-1}, 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}, url = {http://dx.doi.org/10.1126/science.aab1200}, 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}, url = {http://dx.doi.org/10.1163/1568539X-00003203}, 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}, url = {http://dx.doi.org/10.1163/1568539X-00003258}, 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}, url = {http://dx.doi.org/10.1163/1568539X-00003230}, 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}, url = {http://dx.doi.org/10.1163/1568539X-00003263}, 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}, url = {http://dx.doi.org/10.1098/rsbl.2014.0527}, 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}, url = {http://dx.doi.org/10.1037/a0035742}, 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}, url = {http://dx.doi.org/10.1007/s10071-014-0727-2}, 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}, url = {http://dx.doi.org/10.1073/pnas.1323533111}, 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}, url = {http://dx.doi.org/10.1002/dev.21125}, 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}, url = {http://dx.doi.org/10.1086/677209}, 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}, url = {http://dx.doi.org/10.1073/pnas.1316940111}, 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} } @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}, url = {http://dx.doi.org/10.1016/j.physbeh.2013.03.003}, 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}, url = {http://dx.doi.org/10.1371/journal.pone.0066359}, 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} } @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} } @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} } @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}, url = {http://dx.doi.org/10.1007/s10071-013-0633-z}, 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}, url = {http://dx.doi.org/10.1002/ajp.22070}, 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}, 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} } @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}, url = {http://dx.doi.org/10.1016/j.anbehav.2011.12.007}, 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}, url = {http://dx.doi.org/10.1016/j.anbehav.2011.10.026}, 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}, url = {http://dx.doi.org/10.1111/j.1467-7687.2011.01082.x}, 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}, url = {http://dx.doi.org/10.1146/annurev-anthro-081309-145726}, 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}, url = {http://dx.doi.org/10.1016/j.anbehav.2011.01.020}, 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}, 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}, url = {http://dx.doi.org/10.1371/journal.pone.0017147}, 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} } @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}, 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}, url = {http://dx.doi.org/10.1073/pnas.1007411107}, 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} } @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}, url = {http://dx.doi.org/10.1007/s10071-009-0265-5}, 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}, url = {http://dx.doi.org/10.1016/j.cub.2009.12.038}, 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} } @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}, url = {http://dx.doi.org/10.1016/j.cub.2009.11.070}, 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}, url = {http://dx.doi.org/10.1177/0956797609356511}, 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} } @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} } @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}, 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}, url = {http://dx.doi.org/10.1016/j.evolhumbehav.2009.05.003}, 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}, url = {http://dx.doi.org/10.1075/is.10.2.06wob}, 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}, url = {http://dx.doi.org/10.1016/j.beproc.2009.04.003}, 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}, url = {http://dx.doi.org/10.1016/j.jhevol.2008.12.004}, 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} } @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} } @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}, url = {http://dx.doi.org/10.1016/j.jhevol.2008.03.003}, 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}, 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}, url = {http://dx.doi.org/10.1126/science.1154490}, 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}, url = {http://dx.doi.org/10.1016/j.anbehav.2008.05.014}, 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}, url = {http://dx.doi.org/10.1126/science.1146282}, 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}, url = {http://dx.doi.org/10.1371/journal.pbio.0050184}, 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}, url = {http://dx.doi.org/10.1007/s12110-007-9012-2}, 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}, url = {http://dx.doi.org/10.1016/j.cub.2007.02.040}, 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}, url = {http://dx.doi.org/10.1111/j.1467-8721.2007.00476.x}, 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}, url = {http://dx.doi.org/10.1016/j.jhevol.2006.10.001}, 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}, url = {http://dx.doi.org/10.1371/journal.pbio.0050184}, 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}, url = {http://dx.doi.org/10.1016/j.cognition.2005.01.011}, 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}, url = {http://dx.doi.org/10.1016/j.anbehav.2005.09.018}, 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}, url = {http://dx.doi.org/10.1098/rspb.2005.3417}, 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}, url = {http://dx.doi.org/10.1126/science.1123007}, 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}, url = {http://dx.doi.org/10.1016/j.tics.2005.08.009}, 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}, url = {http://dx.doi.org/10.1016/j.tics.2005.07.003}, 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}, url = {http://dx.doi.org/10.1016/j.cub.2005.01.040}, 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}, url = {http://dx.doi.org/10.1016/j.anbehav.2003.11.011}, 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}, url = {http://dx.doi.org/10.1111/j.1467-7687.2004.00368.x}, 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}, url = {http://dx.doi.org/10.1016/S1364-6613(03)00107-4}, 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}, url = {http://dx.doi.org/10.1016/S1364-6613(03)00035-4}, 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}, url = {http://dx.doi.org/10.1006/anbe.2002.2017}, 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}, url = {http://dx.doi.org/10.1126/science.1072702}, 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}, url = {http://dx.doi.org/10.1007/s100710100084}, 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}, url = {http://dx.doi.org/10.1006/anbe.2000.1598}, 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}, url = {http://dx.doi.org/10.1006/anbe.2000.1518}, 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}, url = {http://dx.doi.org/10.1007/s100710000070}, 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}, url = {http://dx.doi.org/10.1080/089106000750051855}, 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}, url = {http://dx.doi.org/10.1006/anbe.1999.1377}, 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}, url = {http://dx.doi.org/10.1037//0735-7036.113.2.173}, 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}, url = {http://dx.doi.org/10.1111/1467-7687.00089}, 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}, url = {http://dx.doi.org/10.1006/anbe.1999.1192}, 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}, url = {http://dx.doi.org/10.1006/anbe.1997.0636}, 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} } %% Books @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}, url = {http://dx.doi.org/10.1093/oso/9780198728511.001.0001}, 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} } @book{fds219139, Author = {B. Hare and V. Woods}, Title = {The Genius of Dogs}, Publisher = {Dutton: Penguin Group}, Year = {2013}, Key = {fds219139} } %% Book Sections/Chapters @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} } @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}, url = {http://dx.doi.org/10.1016/B978-0-12-809633-8.90716-7}, 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} } @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}, url = {http://dx.doi.org/10.1016/B978-0-12-809633-8.90716-7}, 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} } @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}, url = {http://dx.doi.org/10.1093/oso/9780198728511.003.0001}, 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}, url = {http://dx.doi.org/10.1093/oso/9780198728511.003.0006}, 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}, url = {http://dx.doi.org/10.1093/oso/9780198728511.003.0010}, 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} } @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}, url = {http://dx.doi.org/10.1093/oso/9780198728511.003.0018}, 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}, url = {http://dx.doi.org/10.1093/oso/9780198728511.003.0004}, 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}, url = {http://dx.doi.org/10.1093/oso/9780198728511.003.0015}, 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} } @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} } @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} } @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} } @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}, Abstract = {This edited volume is the first of its kind to bridge the epistemological gap between primate ethologists and primate neurobiologists.}, Key = {fds240381} } @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} } @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}, 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} } @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}, url = {http://dx.doi.org/10.1093/acprof:oso/9780195326598.003.0007}, 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} } @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}, url = {http://dx.doi.org/10.1016/B978-0-08-045396-5.00112-3}, 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} } @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} } @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} } @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} } | |
Duke University * Arts & Sciences * Faculty * Staff * Grad * Postdocs * Reload * Login |