Date of Award

Summer 7-14-2011

Degree Type


Degree Name

Master of Arts (MA)



First Advisor

Dr. Sarah F. Brosnan


Humans are exceptional in their willingness to and frequency with which they help one another. However, nonhuman primates also exhibit prosocial behavior. Recently, a number of laboratory studies examining prosociality among primates have yielded conflicting results. These contradictory findings may be due to a reliance on human interaction, tokens, or interactions in the direct context of food, a highly valued resource for animals. The current study examined prosocial behavior among capuchin monkeys (Cebus apella) in a tool task designed to address these issues by examining whether capuchins would transfer a necessary tool to a partner in different payoff conditions. Some capuchins’ behavior indicated that they understood the task, passing the tool when a partner and food were present. Notably, tool transfer in both tasks was overwhelmingly active rather than passive, which is unusual in the context of food; indicating active prosocial behavior is present amongst primates other than cooperative breeders.


Included in

Psychology Commons