Cooperation in Brown Capuchins when Partners Vary

Emory University, Atlanta GA

Investigators

Abstract

Reciprocal exchange of goods and services is a universal human economic activity. In animals, so-called "reciprocal altruism" or "tit-for-tat" is much discussed yet less investigated. It has been theorized that such behavior should occur in animals, at least to some degree: otherwise they could not build the highly cooperative societies that we see. This investigator will investigate cooperation in capuchins (Cebus apella), small monkeys known for their large brains and high intelligence. An apparatus will be installed from which two or more monkeys can obtain food through cooperative effort. Tested in small subgroups, the monkeys can team up with any others present. The development of cooperative partnerships will be followed in detail as well as the tendency to preferentially share pay-offs with helpers. By manipulating partner availability, the investigator be able to measure the long-term impact of cooperation in the larger social group. The proposed experiments seek to illuminate how cooperation arises between individuals, and to what degree it is regulated by tit-for-tat rules. Although the processes are undoubtedly simpler than those underlying the transactions and obligations in human society are, the underlying assumption is that there is a shared psychology that regulates many different kinds of cooperation in a great variety of species. This study will provide a better understanding of how social relationships foster cooperation, and how cooperation affects subsequent social relationships.