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Author de Waal, F.B.M.
Title How animals do business Type Journal Article
Year 2005 Publication Scientific American Abbreviated Journal Sci Am
Volume 292 Issue 4 Pages 54-61
Keywords Animals; Attitude; *Behavior, Animal; Cebus; Cooperative Behavior; *Economics; Emotions; Fishes; Food; Humans; Pan troglodytes; Papio; Social Behavior
Abstract
Address Emory University, USA
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0036-8733 ISBN Medium
Area (up) Expedition Conference
Notes PMID:15915815 Approved no
Call Number refbase @ user @ Serial 166
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Author Brosnan, S.F.; de Waal, F.B.M.
Title Responses to a simple barter task in chimpanzees, Pan troglodytes Type Journal Article
Year 2005 Publication Primates Abbreviated Journal Primates
Volume 46 Issue 3 Pages 173-182
Keywords Analysis of Variance; Animals; Choice Behavior/*physiology; Conditioning (Psychology)/physiology; Learning/*physiology; Pan troglodytes/*physiology; Reward; Sex Factors; *Social Behavior; *Token Economy
Abstract Chimpanzees (Pan troglodytes) frequently participate in social exchange involving multiple goods and services of variable value, yet they have not been tested in a formalized situation to see whether they can barter using multiple tokens and rewards. We set up a simple barter economy with two tokens and two associated rewards and tested chimpanzees on their ability to obtain rewards by returning the matching token in situations in which their access to tokens was unlimited or limited. Chimpanzees easily learned to associate value with the tokens, as expected, and did barter, but followed a simple strategy of favoring the higher-value token, regardless of the reward proffered, instead of a more complex but more effective strategy of returning the token that matched the reward. This response is similar to that shown by capuchin monkeys in our previous study. We speculate that this response, while not ideal, may be sufficient to allow for stability of the social exchange system in these primates, and that the importance of social barter to both species may have led to this convergence of strategies.
Address Living Links, Yerkes National Primate Research Center, Atlanta, GA 30322, USA. sbrosna@emory.edu
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0032-8332 ISBN Medium
Area (up) Expedition Conference
Notes PMID:15824938 Approved no
Call Number refbase @ user @ Serial 167
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Author Brosnan, S.F.; Schiff, H.C.; de Waal, F.B.M.
Title Tolerance for inequity may increase with social closeness in chimpanzees Type Journal Article
Year 2005 Publication Proceedings. Biological sciences / The Royal Society Abbreviated Journal Proc Biol Sci
Volume 272 Issue 1560 Pages 253-258
Keywords Analysis of Variance; Animals; *Attitude; Group Processes; Pan troglodytes/*psychology; Reward; *Social Behavior; Socioeconomic Factors
Abstract Economic decision-making depends on our social environment. Humans tend to respond differently to inequity in close relationships, yet we know little about the potential for such variation in other species. We examine responses to inequity in several groups of chimpanzees (Pan troglodytes) in a paradigm similar to that used previously in capuchin monkeys (Cebus apella). We demonstrate that, like capuchin monkeys, chimpanzees show a response to inequity of rewards that is based upon the partner receiving the reward rather than the presence of the reward alone. However, we also found a great amount of variation between groups tested, indicating that chimpanzees, like people, respond to inequity in a variable manner, which we speculate could be caused by such variables as group size, the social closeness of the group (as reflected in length of time that the group has been together) and group-specific traditions.
Address Yerkes National Primate Research Center, Emory University, 954 North Gatewood Drive, Atlanta, GA 30329, USA. sbrosna@emory.edu
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Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0962-8452 ISBN Medium
Area (up) Expedition Conference
Notes PMID:15705549 Approved no
Call Number refbase @ user @ Serial 169
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Author Brosnan, S.F.; de Waal, F.B.M.
Title A concept of value during experimental exchange in brown capuchin monkeys, Cebus apella Type Journal Article
Year 2004 Publication Folia primatologica; international journal of primatology Abbreviated Journal Folia Primatol (Basel)
Volume 75 Issue 5 Pages 317-330
Keywords Animals; Cebus/*psychology; *Choice Behavior; Female; Food Preferences; *Learning; Male; Sex Factors; Statistics, Nonparametric; *Token Economy; Video Recording
Abstract We evaluated the response of brown capuchin monkeys to two differentially valued tokens in an experimental exchange situation akin to a simple barter. Monkeys were given a series of three tests to evaluate their ability to associate tokens with food, then their responses were examined in a barter situation in which tokens were either limited or unlimited. Capuchins did not perform barter in the typical sense, returning the tokens which were associated with the reward. However, females, but not males, showed a different response, preferring the higher-value token. This may indicate that they learned to prefer one token over the other rather than to associate the tokens with their specific rewards. This sex difference parallels previous findings of greater reciprocity in female brown capuchins than in males.
Address Living Links Center, Emory University, Yerkes National Primate Research Center, 954 N. Gatewood Drive, Atlanta, GA 30329, USA. sbrosna@emory.edu
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0015-5713 ISBN Medium
Area (up) Expedition Conference
Notes PMID:15486443 Approved no
Call Number refbase @ user @ Serial 170
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Author Vokey, J.R.; Rendall, D.; Tangen, J.M.; Parr, L.A.; de Waal, F.B.M.
Title Visual kin recognition and family resemblance in chimpanzees (Pan troglodytes) Type Journal Article
Year 2004 Publication Journal of comparative psychology (Washington, D.C. : 1983) Abbreviated Journal J Comp Psychol
Volume 118 Issue 2 Pages 194-199
Keywords Animals; Female; Male; Pan troglodytes; Random Allocation; *Recognition (Psychology); *Visual Perception
Abstract The male-offspring biased visual kin recognition in chimpanzees (Pan troglodytes) reported by L. A. Parr and F. B. M. de Waal (1999) was replicated with human (Homo sapiens) participants and a principal components analysis (PCA) of pixel maps of the chimpanzee face photos. With the same original materials and methods, both humans and the PCA produced the same asymmetry in kin recognition as found with the chimpanzees. The PCA suggested that the asymmetry was a function of differences in the distribution of global characteristics associated with the framing of the faces in the son and daughter test sets. Eliminating potential framing biases, either by cropping the photos tightly to the faces or by rebalancing the recognition foils, eliminated the asymmetry but not human participants' ability to recognize chimpanzee kin.
Address Department of Psychology and Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada. vokey@uleth.ca
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0735-7036 ISBN Medium
Area (up) Expedition Conference
Notes PMID:15250806 Approved no
Call Number refbase @ user @ Serial 171
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Author Flack, J.C.; Jeannotte, L.A.; de Waal, F.B.M.
Title Play signaling and the perception of social rules by juvenile chimpanzees (Pan troglodytes) Type Journal Article
Year 2004 Publication Journal of comparative psychology (Washington, D.C. : 1983) Abbreviated Journal J Comp Psychol
Volume 118 Issue 2 Pages 149-159
Keywords Age Factors; Animals; Behavior, Animal; Female; Male; Pan troglodytes; *Play and Playthings; Recognition (Psychology); *Signal Detection (Psychology); *Social Perception
Abstract Prescriptive social rules are enforced statistical regularities. The authors investigated whether juvenile chimpanzees (Pan troglodytes) recognize and use enforced statistical regularities to guide dyadic play behavior. They hypothesized (a) that proximity of adults, especially mothers of younger play partners, to play bouts will increase the play signaling of older partners and (b) that when juvenile-juvenile play bouts occur in proximity to adults, older partners will play at a lower intensity than when no adults are present. They found that older and younger partners increase their play signaling in the presence of the mothers of younger partners, particularly as the intensity of play bouts increases. In contrast to their hypothesis, older partners played more roughly when the mothers of younger partners were in proximity. These results suggest that juvenile chimpanzees increase play signaling to prevent termination of the play bouts by mothers of younger partners.
Address Santa Fe Institute, NM 97501, USA. jflack@santafe.edu
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0735-7036 ISBN Medium
Area (up) Expedition Conference
Notes PMID:15250802 Approved no
Call Number refbase @ user @ Serial 172
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Author Brosnan, S.F.; de Waal, F.B.M.
Title Socially learned preferences for differentially rewarded tokens in the brown capuchin monkey (Cebus apella) Type Journal Article
Year 2004 Publication Journal of comparative psychology (Washington, D.C. : 1983) Abbreviated Journal J Comp Psychol
Volume 118 Issue 2 Pages 133-139
Keywords Animals; Behavior, Animal; Cebus; *Choice Behavior; Female; *Learning; Male; *Reward; *Social Behavior
Abstract Social learning is assumed to underlie traditions, yet evidence indicating social learning in capuchin monkeys (Cebus apella), which exhibit traditions, is sparse. The authors tested capuchins for their ability to learn the value of novel tokens using a previously familiar token-exchange economy. Capuchins change their preferences in favor of a token worth a high-value food reward after watching a conspecific model exchange 2 differentially rewarded tokens, yet they fail to develop a similar preference after watching tokens paired with foods in the absence of a conspecific model. They also fail to learn that the value of familiar tokens has changed. Information about token value is available in all situations, but capuchins seem to pay more attention in a social situation involving novel tokens.
Address Living Links Center, Yerkes National Primate Research Center, and Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA 30329, USA. sbrosna@emory.edu
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0735-7036 ISBN Medium
Area (up) Expedition Conference
Notes PMID:15250800 Approved no
Call Number refbase @ user @ Serial 173
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Author Plotnik, J.; Nelson, P.A.; de Waal, F.B.M.
Title Visual field information in the face perception of chimpanzees (Pan troglodytes) Type Journal Article
Year 2003 Publication Annals of the New York Academy of Sciences Abbreviated Journal Ann N Y Acad Sci
Volume 1000 Issue Pages 94-98
Keywords Animals; *Facial Expression; Pan troglodytes; Recognition (Psychology); Visual Fields/*physiology; Visual Perception/*physiology
Abstract Evidence for a visual field advantage (VFA) in the face perception of chimpanzees was investigated using a modification of a free-vision task. Four of six chimpanzee subjects previously trained on a computer joystick match-to-sample paradigm were able to distinguish between images of neutral face chimeras consisting of two left sides (LL) or right sides (RR) of the face. While an individual's ability to make this distinction would be unlikely to determine their suitability for the VFA tests, it was important to establish that distinctive information was available in test images. Data were then recorded on their choice of the LL vs. RR chimera as a match to the true, neutral image; a bias for one of these options would indicate an hemispatial visual field advantage. Results suggest that chimpanzees, unlike humans, do not exhibit a left visual field advantage. These results have important implications for studies on laterality and asymmetry in facial signals and their perception in primates.
Address Department of Animal Science, Cornell University, Ithaca, New York 14853, USA. jmp63@cornell.edu
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0077-8923 ISBN Medium
Area (up) Expedition Conference
Notes PMID:14766624 Approved no
Call Number refbase @ user @ Serial 175
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Author de Waal, F.B.M.
Title Darwin's legacy and the study of primate visual communication Type Journal Article
Year 2003 Publication Annals of the New York Academy of Sciences Abbreviated Journal Ann N Y Acad Sci
Volume 1000 Issue Pages 7-31
Keywords Affect; Aggression/psychology; Animals; Culture; *Evolution; *Facial Expression; Gestures; Grooming; Humans; Laughter; *Nonverbal Communication; Primates/*physiology; Smiling; *Visual Perception
Abstract After Charles Darwin's The Expression of the Emotions in Man and Animals, published in 1872, we had to wait 60 years before the theme of animal expressions was picked up by another astute observer. In 1935, Nadezhda Ladygina-Kohts published a detailed comparison of the expressive behavior of a juvenile chimpanzee and of her own child. After Kohts, we had to wait until the 1960s for modern ethological analyses of primate facial and gestural communication. Again, the focus was on the chimpanzee, but ethograms on other primates appeared as well. Our understanding of the range of expressions in other primates is at present far more advanced than that in Darwin's time. A strong social component has been added: instead of focusing on the expressions per se, they are now often classified according to the social situations in which they typically occur. Initially, quantitative analyses were sequential (i.e., concerned with temporal associations between behavior patterns), and they avoided the language of emotions. I will discuss some of this early work, including my own on the communicative repertoire of the bonobo, a close relative of the chimpanzee (and ourselves). I will provide concrete examples to make the point that there is a much richer matrix of contexts possible than the common behavioral categories of aggression, sex, fear, play, and so on. Primate signaling is a form of negotiation, and previous classifications have ignored the specifics of what animals try to achieve with their exchanges. There is also increasing evidence for signal conventionalization in primates, especially the apes, in both captivity and the field. This process results in group-specific or “cultural” communication patterns.
Address Yerkes Primate Center, and Psychology Department, Emory University, Atlanta, Georgia 30322, USA. dewaal@emory.edu
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0077-8923 ISBN Medium
Area (up) Expedition Conference
Notes PMID:14766618 Approved no
Call Number refbase @ user @ Serial 177
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Author Brosnan, S.F.; De Waal, F.B.M.
Title Monkeys reject unequal pay Type Journal Article
Year 2003 Publication Nature Abbreviated Journal Nature
Volume 425 Issue 6955 Pages 297-299
Keywords Aging; Animals; Cebus/*psychology; Choice Behavior; *Cooperative Behavior; Female; Male; *Reward; Social Justice
Abstract During the evolution of cooperation it may have become critical for individuals to compare their own efforts and pay-offs with those of others. Negative reactions may occur when expectations are violated. One theory proposes that aversion to inequity can explain human cooperation within the bounds of the rational choice model, and may in fact be more inclusive than previous explanations. Although there exists substantial cultural variation in its particulars, this 'sense of fairness' is probably a human universal that has been shown to prevail in a wide variety of circumstances. However, we are not the only cooperative animals, hence inequity aversion may not be uniquely human. Many highly cooperative nonhuman species seem guided by a set of expectations about the outcome of cooperation and the division of resources. Here we demonstrate that a nonhuman primate, the brown capuchin monkey (Cebus apella), responds negatively to unequal reward distribution in exchanges with a human experimenter. Monkeys refused to participate if they witnessed a conspecific obtain a more attractive reward for equal effort, an effect amplified if the partner received such a reward without any effort at all. These reactions support an early evolutionary origin of inequity aversion.
Address Living Links, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30329, USA. sbrosna@emory.edu
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1476-4687 ISBN Medium
Area (up) Expedition Conference
Notes PMID:13679918 Approved no
Call Number refbase @ user @ Serial 179
Permanent link to this record