Primate brain size is predicted by diet but not sociality

@article{DeCasien2017PrimateBS,
  title={Primate brain size is predicted by diet but not sociality},
  author={Alex R. DeCasien and Scott A. Williams and James P. Higham},
  journal={Nature Ecology \&Evolution},
  year={2017},
  volume={1}
}
The social brain hypothesis posits that social complexity is the primary driver of primate cognitive complexity, and that social pressures ultimately led to the evolution of the large human brain. Although this idea has been supported by studies indicating positive relationships between relative brain and/or neocortex size and group size, reported effects of different social and mating systems are highly conflicting. Here, we use a much larger sample of primates, more recent phylogenies, and… 
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