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Stoinski, T. S., & Whiten, A. (2003). Social learning by orangutans (Pongo abelii and Pongo pygmaeus) in a simulated food-processing task. J Comp Psychol, 117(3), 272–282.
Abstract: Increasing evidence for behavioral differences between populations of primates has created a resurgence of interest in examining mechanisms of information transfer between individuals. The authors examined the social transmission of information in 15 captive orangutans (Pongo abelii and Pongo pygmaeus) using a simulated food-processing task. Experimental subjects were shown 1 of 2 methods for removing a suite of defenses on an “artificial fruit.” Control subjects were given no prior exposure before interacting with the fruit. Observing a model provided a functional advantage in the task, as significantly more experimental than control subjects opened the fruit. Within the experimental groups, the authors found a trend toward differences in the actual behaviors used to remove 1 of the defenses. Results support observations from the wild implying horizontal transfer of information in orangutans and show that a number of social learning processes are likely to be involved in the transfer of knowledge in this species.
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de Waal, F. B. (1996). Macaque social culture: development and perpetuation of affiliative networks. J Comp Psychol, 110(2), 147–154.
Abstract: Maternal affiliative relations may be transmitted to offspring, similar to the way in which maternal rank determines offspring rank. The development of 23 captive female rhesus monkeys (Macaca mulatta) was followed from the day of birth until adulthood. A multivariate analysis compared relations among age peers with affiliative relations, kinship, and rank distance among mothers. Maternal relations were an excellent predictor of affiliative relations among daughters, explaining up to 64% of the variance. Much of this predictability was due to the effect of kinship. However, after this variable had been controlled, significant predictability persisted. For relations of female subjects with male peers, on the other hand, maternal relations had no significant predictive value beyond the effect of kinship. One possible explanation of these results is that young rhesus females copy maternal social preferences through a process of cultural learning.
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Weaver, A., & de Waal, F. B. M. (2003). The mother-offspring relationship as a template in social development: reconciliation in captive brown capuchins (Cebus apella). J Comp Psychol, 117(1), 101–110.
Abstract: Mother-offspring (MO) relationship quality was investigated to determine its influence on the development of reconciliation--affiliation between opponents shortly after a fight--because it influenceswhat distressed youngsters learn about calming down. Data were longitudinal and cross-sectional observational samples of 38 MO pairs of monkeys across 24 months. An MO relationship quality index (RQI) classified each pair as secure or insecure. Reconciliation emerged in infancy.Secure youngsters had an appeasing conciliatory style, and insecure youngsters had an agitated conciliatory style. Conclusions are that reconciliation develops from the attachment behavior system and MO RQI is related to the particular conciliatory style youngsters develop by affecting how aroused they are by conflict and the subsequent socializing they seek to calm down.
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Whiten, A., Custance, D. M., Gomez, J. C., Teixidor, P., & Bard, K. A. (1996). Imitative learning of artificial fruit processing in children (Homo sapiens) and chimpanzees (Pan troglodytes). J Comp Psychol, 110(1), 3–14.
Abstract: Observational learning in chimpanzees and young children was investigated using an artificial fruit designed as an analog of natural foraging problems faced by primates. Each of 3 principal components could be removed in 2 alternative ways, demonstration of only one of which was watched by each subject. This permitted subsequent imitation by subjects to be distinguished from stimulus enhancement. Children aged 2-4 years evidenced imitation for 2 components, but also achieved demonstrated outcomes through their own techniques. Chimpanzees relied even more on their own techniques, but they did imitate elements of 1 component of the task. To our knowledge, this is the first experimental evidence of chimpanzee imitation in a functional task designed to simulate foraging behavior hypothesized to be transmitted culturally in the wild.
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Soproni, K., Miklósi, A., Topál, J., & Csányi, V. (2001). Comprehension of human communicative signs in pet dogs (Canis familiaris). J Comp Psychol, 115(2), 122–126.
Abstract: On the basis of a study by D. J. Povinelli, D. T. Bierschwale, and C. G. Cech (1999), the performance of family dogs (Canis familiaris) was examined in a 2-way food choice task in which 4 types of directional cues were given by the experimenter: pointing and gazing, head-nodding (“at target”), head turning above the correct container (“above target”), and glancing only (“eyes only”). The results showed that the performance of the dogs resembled more closely that of the children in D. J. Povinelli et al.'s study, in contrast to the chimpanzees' performance in the same study. It seems that dogs, like children, interpret the test situation as being a form of communication. The hypothesis is that this similarity is attributable to the social experience and acquired social routines in dogs because they spend more time in close contact with humans than apes do, and as a result dogs are probably more experienced in the recognition of human gestures.
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Gosling, S. D. (1998). Personality dimensions in spotted hyenas (Crocuta crocuta). J Comp Psychol, 112(2), 107–118.
Abstract: Personality ratings of 34 spotted hyenas (Crocuta crocuta) were made by 4 observers who knew the animals well. Analyses suggest that (a) hyena personality traits were rated with generally high reliability; (b) 5 broad dimensions (Assertiveness, Excitability, Human-Directed Agreeableness, Sociability, and Curiosity) captured about 75% of the total variance; (c) this dimensional structure could not be explained in terms of dominance status, sex, age, or appearance; and (d) as expected, female hyenas were more assertive than male hyenas. Comparisons with previous research provide evidence for the cross-species generality of Excitability, Sociability, and especially Assertiveness. Discussion focuses on methodological issues in research on animal personality and on the potential contributions this research can make for understanding the biological and environmental bases of personality.
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Flack, J. C., Jeannotte, L. A., & de Waal, F. B. M. (2004). Play signaling and the perception of social rules by juvenile chimpanzees (Pan troglodytes). J Comp Psychol, 118(2), 149–159.
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.
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Hall, C. A., Cassaday, H. J., Vincent, C. J., & Derrington, A. M. (2006). Cone excitation ratios correlate with color discrimination performance in the horse (Equus caballus). J Comp Psychol, 120(4), 438–448.
Abstract: Six horses (Equus caballus) were trained to discriminate color from grays in a counterbalanced sequence in which lightness cues were irrelevant. Subsequently, the pretrained colors were presented in a different sequence. Two sets of novel colors paired with novel grays were also tested. Performance was just as good in these transfer tests. Once the horse had learned to select the chromatic from the achromatic stimulus, regardless of the specific color, they were immediately able to apply this rule to novel stimuli. In terms of the underlying visual mechanisms, the present study showed for the first time that the spectral sensitivity of horse cone photopigments, measured as cone excitation ratios, was correlated with color discrimination performance, measured as accuracy, repeated errors, and latency of approach.
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Schwab, C., & Huber, L. (2006). Obey or not obey? Dogs (Canis familiaris) behave differently in response to attentional states of their owners. J Comp Psychol, 120(3), 169–175.
Abstract: Sixteen domestic dogs (Canis familiaris) were tested in a familiar context in a series of 1-min trials on how well they obeyed after being told by their owner to lie down. Food was used in 1/3 of all trials, and during the trial the owner engaged in 1 of 5 activities. The dogs behaved differently depending on the owner's attention to them. When being watched by the owner, the dogs stayed lying down most often and/or for the longest time compared with when the owner read a book, watched TV, turned his or her back on them, or left the room. These results indicate that the dogs sensed the attentional state of their owners by judging observable behavioral cues such as eye contact and eye, head, and body orientation.
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Brosnan, S. F., & de Waal, F. B. M. (2004). Socially learned preferences for differentially rewarded tokens in the brown capuchin monkey (Cebus apella). J Comp Psychol, 118(2), 133–139.
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.
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