If you have a large Facebook friends list, you probably have a large amygdala.
The amygdala is part of the brain that controls memory and emotions and a new study indicates it's an important part of social behavior.
"We found that amygdala volume correlates with the size and complexity of social networks in adult humans," the study Amygdala Volume and Social Network Size in Humans says.
But don't go on a friending rampage. A larger amygdala doesn't necessarily mean a healthier amygdala.
There is research suggesting we can only manage 150 friendships at once. And there is even a national holiday dedicated to unfriending.