According to the data, when men (but not women) watched a defector get punished, they showed additional activation in reward related areas of the brain, such as the ventral striatum and nucleus accumbens. These are essential elements of the dopamine reward pathway, that same highway of nerves that also gets titillated by sex, drugs and rock n’ roll. Apparently, we are engineered to get pleasure from punishing those who deserve to be punished. —Wired.com.