From buzzing hives, flocking birds to entire forest ecosystems, collectives fascinate, inspire, and challenge scientists to explain how sophisticated group behaviors emerge. How do collective intelligences evolve and what principles shape their emergence? An important yet underexplored component of this question is social structure. Does social structure represent a form of collective intelligence and if so, which features of social structure shape the evolution and success of collectives?

A new project, from a team led by Zanna Clay and Edwin Van Leeuwen at the University of Durham, investigates the drivers of individual and collective intelligences in our close relatives, the great apes. The team hypothesizes that social cohesiveness, social stability and social tolerance shape individuals’ and collectives’ capacities for rationality and reasoning. This project will challenge the dominant paradigm which argues that individual capacities are relatively static, holding instead that there is top-down influence by the social construct on what individuals are able to accomplish. This top-down influence links with the widely-accepted bottom-up influence of individuals on the group to create a dynamic feedback loop. By this account, social structures would become inextricable parts of collective intelligence.

Like humans, great apes live in complex social groups with rich cultural lives and sophisticated cognition, and offer an opportunity to explore social structures from a rich evolutionary lens. This project will study multiple great ape populations to test whether social structure provides a substrate for collective information storage and retrieval with three work packages:

1. The team will explore how minorities or minorities boost or hamper decision-making in different groups of chimpanzees that show a range of social cohesion. The experiment tests a group's flexibility in changing strategy when a minority comes up with a more effective solution to a food-for-token exchange situation. 
2. The team will test if heightened social cohesion allows individuals to rely less on fast, heuristic decision-making. This question builds on the well-established results that stresses of various kinds tend to lead individuals to make non-optimal decisions. Here chimpanzees will have an opportunity to forgo immediate reward in exchange for larger benefit later. The team hypothesizes that in more stable, cohesive groups, such long-term thinking will be more prevalent.
3. Subgroups of chimpanzees will be trained on component elements of a larger puzzle. The team will test the hypothesis that more stable and cohesive groups will more readily combine these elements into an overall solution.