Prosociality, social tolerance and partner choice facilitate mutually beneficial cooperation in common marmosets, Callithrix jacchus

Prosocial motivation has been suggested to facilitate the initiation and maintenance of cooperative interactions, as well as the evolution of social systems reliant on helping behaviour and social coordination. Previous comparative research on the link between prosociality and cooperation has been limited, however, by the absence of directly comparable measures of these traits among the same individuals. In the present study, we therefore examined intraspecific variation in prosociality and cooperative behaviour within a captive colony of group-living, cooperatively breeding common marmosets to provide a direct experimental test of these hypothesized benefits. We measured prosociality using a group service food-provisioning paradigm, and we assessed mutually beneficial dyadic cooperation with the loose string coordinated pulling paradigm. In addition, we also investigated the effects of individual social tolerance and partner choice, which have previously been identified as key factors promoting prosociality and cooperation among primates. As predicted, successful cooperation in the loose string paradigm was positively associated with prosociality, as well as with social tolerance and partner choice. These effects were independent of age, sex, personality, food motivation and learning across experimental sessions. Our results therefore suggest that prosocial motivation, social tolerance and partner choice can each facilitate mutually beneficial cooperation and social coordination in marmosets, supporting the hypothesized role of these mechanisms in the evolution of cooperative behaviour among primates