A comparative study of the cooperative strategies of gibbons, marmosets, and children in response to dyadic and group situational conflict.
Developmental and Educational Psychology
Final Report Abstract
Comparative cognition has mainly focused on the study of great apes and children to shed light on the nature of human cooperation and conflict resolution. However, to understand the evolution of human cooperative traits we cannot only rely on the direct comparisons with our closest living relatives. For instance, chimpanzees may not be the best model to investigate prosocial tendencies from a comparative perspective. Furthermore, convergent evolution of specific social systems such as cooperative breeding might have enhanced prosocial tendencies in humans and marmoset monkeys. To that end, the study of primate species varying in prosocial attitudes and brain size (hence motivational and cognitive components), is a fruitful avenue to understand the influence of these components on individuals’ strategies for coordination and conflict resolution. To that end we have conducted two main studies with gibbons and marmosets. The former are small apes who live in reduced groups and have significantly smaller brains compared to all other ape species (in relation to other apes: similar motivational component, low cognitive component). Marmosets are small brained primates characterized by high in-group prosociality (high motivational component, low cognitive component). In our studies pairs of marmosets and gibbons were presented with a social dilemma where they can decided whether to pay a cost to cooperate or free-ride. The conflict arises when both individuals prefer to free-ride by, for instance, waiting for the partner to act before them. Overall our studies found that marmosets and gibbon strategies were relatively similar to previous results with great apes, in which individuals would cooperate to secure benefits for the self. In that sense, their strategies differed from the cooperative strategies develop by young children. In summary, a cognitive component does not seem to be a crucial aspect to resolve conflicts of interest among non-human primates. In addition, marmoset males seemed to act prosocially towards females, a strategy that fits with the natural history of this specie. In our gibbon study, we also found an effect of time spent living together suggesting that pair-bonding facilitates the resolution of conflicts. Thus, pairbonding and high prosocial motivations might enhance facilitate the resolution of social dilemmas but does not guarantee the development of cooperative strategies distribute rewards equally as human children do. Unfortunately, due to the pandemic we could not pursue our group level projects with primates and humans as planned. Furthermore, testing children in groups was not possible given our infrastructure. Nevertheless, we successfully deviate from our original design by testing children in individual settings on a project investigating the comparative nature of curiosity in conditions of uncertainty—a topic related to the original proposal given the uncertainty nature of children choices in our planned studies. In our set of studies, we found that children were more curious than great apes (tested before the scholarship period by the leading author). They explored uncertainty options significantly more often than great apes even when no information was provided. In addition, the leading author has collaborated with external collaborators on a variety of theoretical projects.
Publications
- (2021). Marmoset monkeys overcome dyadic social dilemmas while avoiding mutual defection. Animal Behaviour, 173, 93-104
Sánchez-Amaro, A., Burkart, J. M., & Rossano, F.
(See online at https://doi.org/10.1016/j.anbehav.2020.12.020) - Gibbon strategies in a food competition task. Scientific Reports
Sánchez-Amaro, A., Ball, R. & Rossano, F.
(See online at https://doi.org/10.1038/s41598-021-88804-5)
