“Yet nonreactive adult humans can excel at purposeful, planned forms of hostility. This kind of proactive aggression is characterized by predetermined goals, premeditated plans of action, attention to the target, and lack of emotional arousal. Chimpanzees sometimes engage in proactive aggression, but humans have taken planned, intentional forms of fighting to new heights such as ambushing, kidnapping, premeditated homicide, and, of course, war. Arguably, hunting and combative sports like boxing are also forms of proactive aggression. And, importantly, hunting and other forms of planned aggression are utterly different psychologically from reactive aggression. Violent criminals, ruthless dictators, torturers, and other proactive aggressors can simultaneously be loving spouses and parents, reliable friends, and patriotic fellow citizens who remain utterly calm and pleasant in situations that would send a chimpanzee or a toddler into a rage. They also don’t need to be as physically powerful.”