The myth of the peace-loving "noble savage" is persistent and pernicious. Indeed, for the last fifty years, most popular and scholarly works have agreed that prehistoric warfare was rare, harmless, unimportant, and, like smallpox, a disease of civilized societies alone. Prehistoric warfare, according to this view, was little more than a ritualized game, where casualties were limited and the effects of aggression relatively mild. Lawrence Keeley's...