If you spend time with a lot of friends, a part of your brain may be unusually large. That part is called the amygdala (uh-MIG'-duh-luh), and it's deep in your brain. Researchers found that among volunteers who got brain scans, those with a bigger amygdala tended to report seeing more friends and family regularly.
Lisa Feldman Barrett of North-eastern University reports the work in a paper published online Sunday by the journal Nature Neuroscience. She says the result makes sense because the amygdala is at the center of a brain network that's important for socialising.
The study couldn't show whether a bigger amygdala leads to more friends, or vice versa. Barrett says the influence might run in both directions.