The roots of war.

• Author: Ehrenreich, Barbara
• Position: Flip Side

Only three types of creatures engage in warfare--humans, chimpanzees, and ants. Among humans, warfare is so ubiquitous and historically commonplace that we are often tempted to attribute it to some innate predisposition for slaughter--a gene, perhaps, manifested as a murderous hormone. The earliest archeological evidence of war is from 12,000 years ago, well before such innovations as capitalism and cities and at the very beginning of settled, agricultural life. Sweeping through recorded history, you can find a predilection for warfare among hunter-gatherers, herding and farming peoples, industrial and even post-industrial societies, democracies, and dictatorships. The good old pop-feminist explanation--testosterone--would seem, at first sight, to fit the facts.

But war is too complex and collective an activity to be accounted for by any warlike instinct lurking within the individual psyche. Battles, in which the violence occurs, are only one part of war, most of which consists of preparation for battle--training, the manufacture of weapons, the organization of supply lines, etc. There is no plausible instinct, for example, that could impel a man to leave home, cut his hair short, and drill for hours in tight formation.

Contrary to the biological theories of war, it is not easy to get men to fight. In recent centuries, men have often gone to great lengths to avoid war--fleeing their homelands, shooting off their index fingers, feigning insanity. So unreliable was the rank and file of the famed eighteenth century Prussian army that military rules forbade camping near wooded areas: The troops would simply melt away into the trees. Even when men are duly assembled for battle, killing is not something that seems to come naturally to them. As Lieutenant Colonel Dave Grossman argued in his book On Killing: The Psychological Cost of Learning to Kill in War and Society (Little, Brown, 1995), one of the great challenges of military training is to get soldiers to shoot directly at individual enemies.

What is it, then, that has made war such an inescapable part of the human experience? Each war, of course, appears to the participants to have an immediate purpose--to crush the "Hun," preserve democracy, disarm Saddam, or whatever--that makes it noble and necessary. But those who study war dispassionately, as a recurrent event with no moral content, have observed a certain mathematical pattern: that of "epidemicity," or the tendency of war to spread in...