Brain structure and social networks

The amygdala is an almond-shaped structure deep within the temporal lobe of the brain. Research on apes and monkeys has shown that the more sociable they are the larger their amygdalas and a new study by researchers at Massachusetts General Hospital suggests that the same may be true of humans. The researchers asked 58 people, between 19 and 83 about the size and complexity of their social networks and gave them an MRI (magnetic-resonance imaging) brain scan. The study found that, on average, the larger people's amygdala was the larger and more complex their social networks were.