The Compassionate Instinct

Why has violence declined? Social psychologists find that at least 80 percent of people have fantasized about killing someone they don’t like. And modern humans still take pleasure in viewing violence, if we are to judge by the popularity of murder mysteries, Shakespearean dramas, Mel Gibson movies, video games, and hockey.

What has changed, of course, is people’s willingness to act on these fantasies. The sociologist Norbert Elias suggested that European modernity accelerated a “civilizing process” marked by increases in self-control, long-term planning, and sensitivity to the thoughts and feelings of others. These are precisely the functions that today’s cognitive neuroscientists attribute to the prefrontal cortex. But this only raises the question of why humans have increasingly exercised that part of their brains. No one knows why our behavior has come under the control of the better angels of our nature, but there are four plausible suggestions.

The first is that the seventeenth-century philosopher Thomas Hobbes got it right. Life in a state of nature is nasty, brutish, and short—not because of a primal thirst for blood but because of the inescapable logic of anarchy. Any beings with a modicum of self-interest may be tempted to invade their neighbors and steal their resources. The resulting fear of attack will tempt the neighbors to strike first in preemptive self-defense, which will in turn tempt the first group to strike against them preemptively, and so on. This danger can be defused by a policy of deterrence—don’t strike first, retaliate if struck—but to guarantee its credibility, parties must avenge all insults and settle all scores, leading to cycles of bloody vendetta.

These tragedies can be averted by a state with a monopoly on violence. States can inflict disinterested penalties that eliminate the incentives for aggression, thereby defusing anxieties about preemptive attack and obviating the need to maintain a hair-trigger propensity for retaliation. Indeed, Manuel Eisner attributes the decline in European homicide to the transition from knightly warrior societies to the centralized governments of early modernity. And today, violence continues to fester in zones of anarchy, such as frontier regions, failed states, collapsed empires, and territories contested by mafias, gangs, and other dealers of contraband.

James Payne suggests another possibility: that the critical variable in the indulgence of violence is an overarching sense that life is cheap. When pain and early death are everyday features of one’s own life, one feels less compunction about inflicting them on others. As technology and economic efficiency lengthen and improve our lives, we place a higher value on life in general.

A third theory, championed by journalist Robert Wright, invokes the logic of nonzero-sum games: scenarios in which two agents can each come out ahead if they cooperate, such as trading goods, dividing up labor, or sharing the peace dividend that comes from laying down their arms. As people acquire know-how that they can share cheaply with others and develop technologies that allow them to spread their goods and ideas over larger territories at lower cost, their incentive to cooperate steadily increases, because other people become more valuable alive than dead.

Then there is the scenario sketched by philosopher Peter Singer. Evolution, he suggests, bequeathed people a small kernel of empathy, which by default they apply only within a narrow circle of friends and relations. Over the millennia, people’s moral circles have expanded to encompass larger and larger polities: the clan, the tribe, the nation, both sexes, other races, and even animals. The circle may have been pushed outward by expanding networks of reciprocity, à la Wright, but it might also be inflated by the inexorable logic of the Golden Rule: the more one knows and thinks about other living things, the harder it is to privilege one’s own interests over theirs. The empathy escalator may also be powered by cosmopolitanism, in which journalism, memoir, and realistic fiction make the inner lives of other people, and the precariousness of one’s own lot in life, more palpable—the feeling that “there but for fortune go I.”

Whatever its causes, the decline of violence has profound implications. It is not a license for complacency: we enjoy the peace we find today because people in past generations were appalled by the violence in their time and worked to end it, and so we should work to end the appalling violence in our time. Nor is it necessarily grounds for optimism about the immediate future, since the world has never before had national leaders who combine premodern sensibilities with modern weapons.