Amygdala Volume and Social Network Size in Humans

We demonstrated that amygdala volume (corrected for total intracranial volume) positively correlated with the size and complexity of social networks in adult humans ranging in age from 19 to 83 years. This relationship was specific to the amygdala as compared to other subcortical structures. An exploratory analysis of the entire cortical mantle also revealed an association between social network variables and cortical thickness in three cortical areas, two of which share dense connectivity with the amygdala. Amygdala volume was not related to other social variables such as life satisfaction or social support. These findings converge with data from functional neuroimaging and lesion neuropsychology indicating that the amygdala plays an important role in brain networks contributing to social behavior.