This study examined whether the social brain hypothesis is applicable to human individual differences. The results indicated that Sociability correlated positively with the examined brain structures (controlling for the effects of body size differences and age effects). Sociability correlated most strongly with the left and right temporal lobes and neocortex, but also with the left and right frontal lobes and cerebrum. Unfortunately, the study had a relatively low sample size, and so the authors urged caution in interpreting the results and emphasized the need for further follow-up studies.
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