Social networks and the size of certain brain structures.

Many recent studies in humans have found a connection between the size of people's social networks and the size of certain brain structures.

In fact, Barrett herself has shown that people with larger and more complex social networks have larger amygdalas, a part of the brain involved in processing social cues.

“These findings do strongly suggest that people who are exposed to larger and more complex social grouping will develop changes in their brain structures, that will be measurable and have visible effects in terms of emotional processing, and social ability,” she said.

Those with fewer social interactions early in life might be at a disadvantage later, said Robin Dunbar, a cultural anthropologist at Oxford University. He said this was an especially big concern today, when so many children spend so much time online, engaging in virtual interactions.

http://www.pri.org/stories/health/global-health/larger-social-networks-especially-earlier-in-life-leads-to-larger-brain-development-6781.html