Abstract # 6317 Poster # 192:

Scheduled for Friday, June 19, 2015 06:00 PM-08:00 PM: (Cascade AJBCD) Poster Presentation


CAPUCHIN MONKEYS (CEBUS APELLA) DO NOT DELIVER FOOD TO PARTNERS IN A BAR-PULL TASK

B. J. MacDonald1, C. F. Talbot1, L. Prétôt1 and S. F. Brosnan1,2
1Georgia State University, Dept. of Psychology, P.O. Box 5010, Atlanta, Georgia 30302, USA, 2Georgia State University, Dept. of Philosophy & Neuroscience Institute
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     Altruistic behavior is thought to have evolved to help kin and those likely to return the favor. However, the proximate mechanisms underlying altruistic behavior have proved difficult to uncover. Here, we examined low-cost altruism in a prosocial species, capuchin monkeys. Using a bar-pull apparatus, a subject (operator) was given the opportunity to deliver food to a partner (recipient) at a small cost to itself. By manipulating the recipient’s access to food, we examined whether operators were sensitive to their partner’s needs. We predicted if the operators paid attention to recipients’ needs, the operators would pull more often when the recipients could access the food than when the recipients could not. Overall, the operators’ pulling behavior varied among the five conditions (Friedman’s test, chi2(4)=33.96, p<0.001). Operators pulled significantly more when they could access food themselves compared to when the recipient was absent and food was inaccessible (Wilcoxon signed-rank test, Z=-2.93, p=.003), suggesting the capuchins understood the contingencies of the task. Although operators pulled significantly more often when the recipients could access food compared to the baseline condition (Z=-3.36, p=.001), they were no more likely to deliver rewards to their partners when food was accessible compared to when food was inaccessible (Z=-1.66, p=.09). Thus, although operators understood the task and were generally prosocial, they did not attend to specific needs of recipients.