The psychology of cooperation in animals: an ecological approach

There has been a recent push to study the psychological processes supporting cooperation in nonhuman animals. However, progress has been limited thus far due to differences in approaches between psychologists and behavioral ecologists. Although the former tend to use controlled experiments to pinpoint precise cognitive mechanisms, these experiments often lack ecological validity. In contrast, behavioral ecologists seek to understand the adaptive function of cooperative behavior of animals in the wild but typically neglect the underlying psychological mechanisms. Here we appraise and integrate evidence from these two approaches to understand the potential cognitive solutions to four fundamental challenges that animals face during cooperative interactions under natural conditions: (1) when to cooperate; (2) with whom to cooperate; (3) what to do in cooperative interactions; (4) how much to contribute to cooperation. We argue that an ecologically motivated approach is critical to understanding the psychological mechanisms of cooperation and how these mechanisms evolve.