The Beast Within Why Men Are Violent Author:Neil Boyd What causes male violence...and how can we stop it? A provocative study suggests that biology plays a definitive role in engendering murder, rape, torture, and other vicious acts. To understand brutality, start with the animal world, where male aggression ensures the survival of the species and primacy within the group. Uncover testosterone's po... more »werful effects, the connection between the number of teenage boys in the population and patterns of violence, and (because biology is not destiny) how we can reduce lethal aggression.« less