Researchers at Massachusetts General Hospital in Boston have found that the amygdalas (an almond-shaped clump of nerves at the base of your brain) of highly socialized people are larger than those of their more reclusive counterparts.
Amygdala volume has been connected to social network and behavior in past research, as scientists have found that nonhuman primate species with larger social groups tend to have greater amygdala volumes. Kevin Bickart and his coauthors took the next logical step and examined how amygdala volume varies in humans with different social networks. Their results appear in a recent issue of Nature Neuroscience.
Social network size and complexity did not significantly correspond with the size of the hippocampus or other subcortical areas. The authors did find that three regions in the cerebral cortex of the brain (caudal inferior temporal sulcus, caudal superior frontal gyrus, and subgenual anterior cingulate cortex) might correlate with social networks. They propose that those regions might have evolved along with amygdala to deal with the complexities of growing social circles.
This is one of the first publications that demonstrates a relationship between amygdala volume and social networks in humans. It would be fascinating to determine if a cause and effect relationship can be established. Are certain people born with larger amygdala and therefore create bigger social networks, or does the amygdala grow as we gain more friends and foes?
Read the full story on: http://arstechnica.com