On Killing: The Psychological Cost of Learning to Kill in War and Society

by Dave Grossman

using the chariot in pursuit and shooting men in the back—but the key issue is that the chariot crew traditionally consisted of two men: a driver and an archer. And this was all that was needed to provide the same accountability and diffusion of responsibility that, in World War II, permitted nearly 100 percent of crew-served weapons (such as machine guns) to fire while only 15 to 20 percent of the riflemen fired. The chariot was defeated by the phalanx, which succeeded by turning the whole formation into a massive crew-served weapon. Although he did not have the designated leaders of the later Roman formations, each man in the phalanx was under a powerful mutual surveillance system, and in the charge it would be hard to fail to strike home without having others notice that your spear had been raised or dropped at the critical moment. And, of course, in addition to this accountability system the closely packed phalanx provided a high degree of mob anonymity. For nearly half a millennium the Romans’ professional military (with, among other things, their superior application of leadership) eclipsed the phalanx in the Western way of war. But the phalanx’s application of group processes was so simple and so effective that during the