British Academy: The UK's National Academy for the Humanities and Social Sciences
Social Brain, Distributed Mind
Abstract
Social complexity and the importance of indirect relationships: social networks in primates
Julia Lehmann (Roehampton)
The Machiavellian Intelligence Hypothesis suggests that primates need large brains in order to deal with complex social relationships. However, we know very little about the nature of this complexity and, in the past, group size has often been used as a proxy for social complexity. In this study we use social network analysis across a wide range of primate taxa to analyse which features of primate social networks correlate with brain size and how these may be related to social complexity. I suggest that more complex societies are characterised by a high number of indirect relationships where individuals are members of the same social group but do not maintain close social bonds with all others. Because such indirect relationships need to be monitored, nevertheless they may pose an important selection pressure on social cognition. Large spatio-temporal variability in group cohesion, as found in chimpanzee and human societies, may additionally enhance the effect.