Pulling a gun's trigger can be an appalling act. But if it is suicidal drawing fire to save someone, it has an utterly different meaning. Placing your hand on someone's arm can be an act of deep compassion or the first step of betrayal. The punch line? It's all about context, and the biology of context is vastly more complicated than the biology of the behavior itself.

An open mind is a prerequisite to an open heart.

Give lab rats oxytocin and, according to that meme, they get better at talking about their feelings and sing like Joan Baez.

What happened in the milliseconds before a behavior to cause it? That's in the neurobiological realm.

Individual differences in testosterone level predict very little about differences in aggression.

...I might continue to believe that there is no god even if it were proved that there is. A religious friend of mine once remarked that the concept of god is useful, because you can berate god during the bad times. But it is clear to me that I don't need to believe there is a god in order to berate him.

We all seek out stress. We hate the wrong kinds of stress but when it's the right kind, we love it - we pay good money to be stressed by a scary movie, a roller coaster ride, a challenging puzzle.