Marmoset monkeys overcome dyadic social dilemmas while avoiding mutual defection

Social primates constantly face situations in which their preferences collide and they need to engineer strategies overcome conflicts of interest. Studies with chimpanzees, Pan troglodytes, have found that use competitive social dilemmas, maximizing own benefits while minimizing the loss rewards. However, little is known about how other rely more on cooperation would similar dilemmas. We therefore presented male–female pairs common marmosets, Callithrix jacchus (cooperative breeders) two experiments an action-based paradigm creates a conflict interest over access unequal reward distribution. Rather than engaging mutual defection, marmosets were able this dilemma time, by developing mix strategic behaviours (predominantly females) tolerance disadvantageous distributions males). This behavioural yielded better rewards for females. Importantly, such net outcome consistent natural history species where females, who carry high energetic burden reproduction, tend be less prosocial are receivers, rather donors, food-sharing events among adults.