12/18/2011 11:43 am ET | Updated Dec 19, 2011

Testosterone: 13 Surprising Facts

By Anne Harding

When most people hear the word testosterone, they think of aggressive behavior. There is a link between the two -- at least in competitive situations, such as with a peer or for a sexual partner.

However, there appears to be a subtler interplay between testosterone and behavior in other types of situations -- in both men and women.

Here are a few facts about the "male hormone."

surprising testosterone facts