The Investigation of Prosocial Behavior in a Tool Task by Capuchin Monkeys (Cebus Apella)

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. INDEX WORDS: Prosocial behavior, Tool use, Cooperation, Altruism, Mutualism, Reciprocity, Nonhuman primate, Capuchin monkeys THE INVESTIGATION OF PROSOCIAL BEHAVIOR IN A TOOL TASK BY CAPUCHIN MONKEYS (CEBUS APELLA)