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Fragaszy, D. M., & Visalberghi E. (1989). Social influences on the acquisition of tool-using behaviors in tufted capuchin monkeys (Cebus apella). J. Comp. Psychol., 103(2), 159–170.
Abstract: To identify behaviors related to acquisition of tool-use in tufted capuchins (Cebus apella), we presented two tool-using tasks to two groups, extending findings by Westergaard and Fragaszy (1987) and Visalberghi (in press). Five Ss learned to use the tools in each task. The primary predictor of success was level of interest in the task. Observation of others at the apparatus did not facilitate exploratory behaviors or contact with the tools in the observers. Most animals performed exploratory behaviors more often when they were at the apparatus alone than when with another, whether or not the other was using a tool. Observers were quick to learn the relationship between another's activities and the appearance of food. We conclude that capuchins do not readily learn about instrumental relations by observation of others or imitate other's acts. Imitation probably plays no role in the spread of novel instrumental behaviors among monkeys. (PsycINFO Database Record (c) 2010 APA, all rights reserved)
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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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Dorrance, B. R., & Zentall, T. R. (2002). Imitation of conditional discriminations in pigeons (Columba livia). J Comp Psychol, 116(3), 277–285.
Abstract: In the present experiments, the 2-action method was used to determine whether pigeons could learn to imitate a conditional discrimination. Demonstrator pigeons (Columba livia) stepped on a treadle in the presence of 1 light and pecked at the treadle in the presence of another light. Demonstration did not seem to affect acquisition of the conditional discrimination (Experiment 1) but did facilitate its reversal of the conditional discrimination (Experiments 2 and 3). The results suggest that pigeons are not only able to learn a specific behavior by observing another pigeon, but they can also learn under which circumstances to perform that behavior. The results have implications for proposed mechanisms of imitation in animals.
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Dorrance, B. R., & Zentall, T. R. (2001). Imitative learning in Japanese quail (Coturnix japonica) depends on the motivational state of the observer quail at the time of observation. J Comp Psychol, 115(1), 62–67.
Abstract: The 2-action method was used to examine whether imitative learning in Japanese quail (Coturnix japonica) depends on the motivational state of the observer quail at the time of observation of the demonstrated behavior. Two groups of observers were fed before observation (satiated groups), whereas 2 other groups of observers were deprived of food before observation (hungry groups). Quail were tested either immediately following observation or after a 30-min delay. Results indicated that quail in the hungry groups imitated, whereas those in the satiated groups did not, regardless of whether their test was immediate or delayed. The results suggest that observer quail may not learn (through observation) behavior that leads to a reinforcer for which they are unmotivated at the time of test. In addition, the results show that quail are able to delay the performance of a response acquired through observation (i.e., they show deferred imitation).
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Dorey, N. R., Conover, A. M., & Udell, M. A. R. (2014). Interspecific communication from people to horses (Equus ferus caballus) is influenced by different horsemanship training styles. J. Comp. Psychol., 128(4), 337–342.
Abstract: The ability of many domesticated animals to follow human pointing gestures to locate hidden food has led to scientific debate on the relative importance of domestication and individual experience on the origins and development of this capacity. To further explore this question, we examined the influence of different prior training histories/methods on the ability of horses (Equus ferus caballus) to follow a momentary distal point. Ten horses previously trained using one of two methods (Parelli™ natural horsemanship or traditional horse training) were tested using a standard object choice task. The results show that neither group of horses was initially able to follow the momentary distal point. However, after more experience with the point, horses previously trained using the Parelli natural horsemanship method learned to follow momentary distal points significantly faster than those previously trained with traditional methods. The poor initial performance of horses on distal pointing tasks, coupled with the finding that prior training history and experimental experience can lead to success on this task, fails to support the predictions of the domestication hypothesis and instead lends support to the two-stage hypothesis. (PsycINFO Database Record (c) 2016 APA, all rights reserved)
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Devenport, J. A., Patterson, M. R., & Devenport, L. D. (2005). Dynamic averaging and foraging decisions in horses (Equus callabus). J. Comp. Psychol., 119(3), 352–358.
Abstract: The variability of most environments taxes foraging decisions by increasing the uncertainty of the information available. One solution to the problem is to use dynamic averaging, as do some granivores and carnivores. Arguably, the same strategy could be useful for grazing herbivores, even though their food renews and is more homogeneously distributed. Horses (Equus callabus) were given choices between variable patches after short or long delays. When patch information was current, horses returned to the patch that was recently best, whereas those without current information matched choices to the long-term average values of the patches. These results demonstrate that a grazing species uses dynamic averaging and indicate that, like granivores and carnivores, they can use temporal weighting to optimize foraging decisions.
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de Waal, F. B. (1997). Food transfers through mesh in brown capuchins. J Comp Psychol, 111(4), 370–378.
Abstract: Capuchin monkeys (Cebus apella) share food even if their partner is behind a mesh restraint. Pairs of adult capuchins were moved into a test chamber in which 1 monkey received cucumber pieces for 20 min and the other received apple slices during the following 20 min. Tolerant transfers of food occurred reciprocally among females: The rate of transfer from Female B to A in the second test phase varied with the rate from Female A to B in the first test phase. Several social mechanisms may explain this reciprocity. Whereas this study does not contradict cognitively complex explanations (e.g., mental record keeping of given and received food), the results are consistent with a rather simple explanation: that food sharing reflects a combination of affiliative tendency and high tolerance. The study suggests that sharing mechanisms may be different for adult male capuchins, with males sharing food more readily and less discriminatingly than females.
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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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Custance, D., Whiten, A., & Fredman, T. (1999). Social learning of an artificial fruit task in capuchin monkeys (Cebus apella). J. Comp. Psychol., 113(1), 13–23.
Abstract: Social learning in 11 human-raised capuchin monkeys (Cebus apella) was investigated using an artificial fruit that was designed as an analogue of natural foraging problems faced by primates. Each subject observed a human model open each of 3 principal components on the fruit in 1 of 2 alternative ways (“morphs”). The capuchin monkeys reproduced, to differing extents, the alternative techniques used for opening 1 component of the task (poking vs. pulling while twisting out a pair of smooth plastic bolts) but not the other 2. From the subjects' actions on the bolt latch, independent coders could recognize which morph they had witnessed, and they observed a degree of matching to the demonstrator's act consistent with simple imitation or object movement reenactment (A learns from watching B how an object, or parts of an object, move). Thus, these capuchins were capable of more complex social learning than has been recently ascribed to monkeys. (PsycINFO Database Record (c) 2016 APA, all rights reserved)
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Cheney, D. L., Seyfarth, R. M., & Silk, J. B. (1995). The responses of female baboons (Papio cynocephalus ursinus) to anomalous social interactions: evidence for causal reasoning? J Comp Psychol, 109(2), 134–141.
Abstract: Baboons' (Papio cynocephalus ursinus) understanding of cause-effect relations in the context of social interactions was examined through use of a playback experiment. Under natural conditions, dominant female baboons often grunt to more subordinate mothers when interacting with their infants. Mothers occasionally respond to these grunts by uttering submissive fear barks. Subjects were played causally inconsistent call sequences in which a lower ranking female apparently grunted to a higher ranking female, and the higher ranking female apparently responded with fear barks. As a control, subjects heard a sequence made causally consistent by the inclusion of grunts from a 3rd female that was dominant to both of the others. Subjects responded significantly more strongly to the causally inconsistent sequences, suggesting that they recognized the factors that cause 1 individual to give submissive vocalizations to another.
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