A large portion of mammals live in groups. Yet, species vary dramatically both in their degree of group-level cooperation and the extent to which they approach intergroup interactions with tolerance or hostility. Surprisingly, in most taxa besides humans, little is known about the psychological mechanisms that determine perception of social groups and drive species-specific patterns of both group cooperation and intergroup interaction. That is, we still know very little about how animals think at the level of groups, both about their own groups and about neighboring outgroups, nor which combination of cognitive and physiological mechanisms determine whether intergroup relations are largely tolerant or hostile. 

The goal of this project, from a team led by Chris Krupenye (Johns Hopkins University) in collaboration with James Brooks, is to explore the foundational cognitive mechanisms that influence the formation and boundaries of groups. 

The project aims to build a framework and overarching theory for the evolution of group-mindedness using comparative approaches. This would provide a basis for a unified understanding of the mechanisms that shape group connection and differentiation.

To do this, the team will conduct a three-part comparative study involving humans, chimpanzees, and bonobos:

1. Investigate the structure of nonhuman group-mindedness by experimentally testing multiple competing hypotheses about how chimpanzees (an optimal candidate for group-mindedness) mentally represent social groups

2. Test the links between group-mindedness and potential evolutionary bases, through comparisons between chimpanzees and bonobos, who differ in both group-level competitive and cooperative behavior

3. Determine how mental representations of social groups are formed and which cues determine the assignment of shared group membership

Overall, the aim is to provide insight on the mechanisms that underlie our connection to others and that influence the formation and boundaries of groups.

Photo credit: Aaron Sandel