Most of us assume that one of the reasons men tend to act aggressively is that men have higher levels of testosterone. Let's take a look at this "testosterone myth" because this isn't always the case. In fact, in some cases, the higher levels of testosterone actually cause men to be MORE NICE than usual. Don't believe it? Let's take a look at what author Robert Sapolsky has to teach us about the true and subtle effects of testosterone in his book, Behave: The Biology of Humans at our Best and Worst. I think you'll be surprised.
Psychology in Everyday Life: The Psych Files