Social Brain Hypothesis

The social brain hypothesis argues the computational demands of living in highly complex social groups selected for overall increases in primate brain volume—including humans—explaining in large part the unusually large brains of many primate species. In particular, among both corvids and anthropoid primates, unusually high encephalization seems to be associated with complex social systems that involve strong social bonds between group members of both sexes. The entry surveys current research from primatology, social psychology, comparative animal behavior, evolutionary anthropology, behavioral endocrinology, social cognitive neuroscience, developmental psychology, and psychopathology, all of which offer substantive evidence in support of this hypothesis. Suggestions are offered for further readings, including alternative hypotheses for this proposal.