Biological explanation

A recent episode of This American Life dealt with the issue of testosterone. A researcher in the field and the author of Heroes, Rogues and Lovers: Testosterone and Behavior was discussing how testosterone varying levels impact behavior.

He described people with naturally high levels of testosterone as being characterized by boldness, fearlessness, confidence, a willingness to speak one's mind, and a tendency to move things forward with little hesitancy or indecision. However, the drawback...