The Skillful and the Stingy: Partner Choice Decisions and Fairness Intuitions Suggest Human Adaptation for a Biological Market of Cooperators

Despite the importance of human cooperation, the psychological mechanisms by which humans choose their cooperative partners and divide the spoils of cooperation are still unclear. To address these questions, we first contextualize human cooperation within biological market theory and then present results from a series of economic games in which we test how a cooperative partner’s generosity and productivity affect their desirability as a partner and intuitions about how entitled they are to keep the spoils of cooperation. We found that the evaluation of productivity and generosity cannot be fully explained by the incentive structure of the game, but appeared calibrated for choosing long-term cooperative partners and dividing cooperatively created resources within a biological market. Specifically, productivity mattered more to men than to women, and productivity mattered more when it revealed underlying skill rather than luck. In addition, generosity had far larger effects than productivity, but the effect of productivity was moderated by generosity, suggesting sophisticated heuristics for choosing cooperative partners. We discuss implications of our data for the study of social perception and suggest avenues for future research.