The Better Angels of Our Nature: Why Violence Has Declined

by Steven Pinker

When a tendency toward violence evolves, it is always strategic. Organisms are selected to deploy violence only in circumstances where the expected benefits outweigh the expected costs. That discernment is especially true of intelligent species, whose large brains make them sensitive to the expected benefits and costs in a particular situation, rather than just to the odds averaged over evolutionary time. The logic of violence as it applies to members of an intelligent species facing other members of that species brings us to Hobbes. In a remarkable passage in Leviathan (1651), he used fewer than a hundred words to lay out an analysis of the incentives for violence that is as good as any today: So that in the nature of man, we find three principal causes of quarrel. First, competition; secondly, diffidence; thirdly, glory. The first maketh men invade for gain; the second, for safety; and the third, for reputation. The first use violence, to make themselves masters of other men’s persons, wives, children, and cattle; the second, to defend them; the third, for trifles, as a word, a smile, a different opinion, and any other sign of undervalue, either direct in their persons or by reflection in their kindred, their friends, their nation, their profession, or their name.5