The psychological mechanisms underlying reciprocal prosociality in chimpanzees (Pan troglodytes)

In both the wild and captivity, chimpanzees engage in reciprocal patterns of prosocial behavior. However, the proximate mechanisms underlying these patterns are unclear. In the current study, we investigated whether chimpanzees prefer to act prosocially toward conspecifics who have directly benefited them (perhaps based on an affective bond) or whether they simply observe the prosocial behavior of others in general (including indirectly to third parties) and preferentially interact with and behave prosocially toward the most prosocial individuals. We found good evidence for direct reciprocity but little evidence for a general (indirect) preference for prosocial individuals. These results suggest that cooperative reciprocity in chimpanzees may be based mostly on social-affective processes and direct interactions. (PsycInfo Database Record (c) 2020 APA, all rights reserved).