Group Size Predicts Social but Not Nonsocial Cognition in Lemurs.

Published

Journal Article

The social intelligence hypothesis suggests that living in large social networks was the primary selective pressure for the evolution of complex cognition in primates. This hypothesis is supported by comparative studies demonstrating a positive relationship between social group size and relative brain size across primates. However, the relationship between brain size and cognition remains equivocal. Moreover, there have been no experimental studies directly testing the association between group size and cognition across primates. We tested the social intelligence hypothesis by comparing 6 primate species (total Nā€Š=ā€Š96) characterized by different group sizes on two cognitive tasks. Here, we show that a species' typical social group size predicts performance on cognitive measures of social cognition, but not a nonsocial measure of inhibitory control. We also show that a species' mean brain size (in absolute or relative terms) does not predict performance on either task in these species. These data provide evidence for a relationship between group size and social cognition in primates, and reveal the potential for cognitive evolution without concomitant changes in brain size. Furthermore our results underscore the need for more empirical studies of animal cognition, which have the power to reveal species differences in cognition not detectable by proxy variables, such as brain size.

Full Text

Duke Authors

Cited Authors

  • Maclean, EL; Sandel, AA; Bray, J; Oldenkamp, RE; Reddy, RB; Hare, BA

Published Date

  • January 2013

Published In

Volume / Issue

  • 8 / 6

Start / End Page

  • e66359 -

PubMed ID

  • 23840450

Pubmed Central ID

  • 23840450

Electronic International Standard Serial Number (EISSN)

  • 1932-6203

International Standard Serial Number (ISSN)

  • 1932-6203

Digital Object Identifier (DOI)

  • 10.1371/journal.pone.0066359

Language

  • eng