Testing the cognitive components of primate cooperation

Reciprocal cooperation is a prominent characteristic of primate behavior, but its proximate bases have been largely neglected. In this project, we will investigate the role of advanced cognition in primate cooperation. We will test the ability of tufted capuchin monkeys to engage in calculated reciprocity, and will explore the role of self-control in constraining their ability to cooperate while facing a conflict of interests.

First, we will test if cooperative behavior in capuchins can be motivated by the expectation of reciprocation. Monkeys will be tested under conditions that allow or do not allow reciprocation. If what motivates monkeys to cooperate is the expectation of reciprocation, they will cooperate more under conditions that allow reciprocity.

Second, we will test whether capuchins can adopt flexible strategies in a cooperative task that involves a conflict of interest, and the role of self-control. The task will simulate a Snowdrift Game in which the best strategy is to defect, but if both partners defect none gets any reward.

During the test, two monkeys will pull a rope in order to obtain a reward for self and for a partner, but the relative size of the two rewards will depend on the experimental condition. An accumulation task will be used to measure self-control. If monkeys adapt flexibly to the cooperation task, their latency to pull the rope will vary with the experimental condition. If their success is constrained by their lack of self-control, latencies to pull will be modulated by self-control, as measured by the accumulation task. This project will contribute to understanding the extent to which human cooperativeness shares a motivational and cognitive basis with our close phylogenetic relatives.