Contrary to assumptions, virtually everyone who does not fall into the rare breed of aggressive psychopaths who kill with ease has to be trained to kill. To the chagrin of military trainers and leaders throughout history, humans have an innate aversion to taking of human life. Untrained soldiers are historically averse to killing the “enemy” even when their life is in direct danger. Most will hide, duck, fire in the air, load and unload their weapons repeatedly, fire over the heads of the “enemy” and take other evasive actions, anything, to avoid killing. For example, in World War II, only about 20 percent of the riflemen were found to actually fire their weapons directly at enemy soldiers.