Is Violence History?
By PETER SINGER
THE BETTER ANGELS OF OUR NATURE
Why Violence Has Declined
By Steven Pinker
Illustrated. 802 pp. Viking. $40.
It is unusual for the subtitle of a book to undersell it, but Steven Pinker’s “Better Angels of Our Nature” tells us much more than why violence has declined. Pinker, a professor of psychology at Harvard who first became widely known as the author of“The Language Instinct,” addresses some of the biggest questions we can ask: Are human beings essentially good or bad? Has the past century witnessed moral progress or a moral collapse? Do we have grounds for being optimistic about the future?
If that sounds like a book you would want to read, wait, there’s more. In 800 information-packed pages, Pinker also discusses a host of more specific issues. Here is a sample: What do we owe to the Enlightenment? Is there a link between the human rights movement and the campaign for animal rights? Why are homicide rates higher in the southerly states of this country than in northern ones? Are aggressive tendencies heritable? Could declines in violence in particular societies be attributed to genetic change among its members? How does a president’s I.Q. correlate with the number of battle deaths in wars in which the United States is involved? Are we getting smarter? Is a smarter world a better world?
In seeking answers to these questions Pinker draws on recent research in history, psychology, cognitive science, economics and sociology. Nor is he afraid to venture into deep philosophical waters, like the role of reason in ethics and whether, without appealing to religion, some ethical views can be grounded in reason and others cannot be.
The central thesis of “Better Angels” is that our era is less violent, less cruel and more peaceful than any previous period of human existence. The decline in violence holds for violence in the family, in neighborhoods, between tribes and between states. People living now are less likely to meet a violent death, or to suffer from violence or cruelty at the hands of others, than people living in any previous century.
Pinker assumes that many of his readers will be skeptical of this claim, so he spends six substantial chapters documenting it. That may sound like a hard slog, but for anyone interested in understanding human nature, the material is engrossing, and when the going gets heavy, Pinker knows how to lighten it with ironic comments and a touch of humor.
Pinker begins with studies of the causes of death in different eras and peoples. Some studies are based on skeletons found at archaeological sites; averaging their results suggests that 15 percent of prehistoric humans met a violent death at the hands of another person. Research into contemporary or recent hunter-gatherer societies yields a remarkably similarly average, while another cluster of studies of pre-state societies that include some horticulture has an even higher rate of violent death. In contrast, among state societies, the most violent appears to have been Aztec Mexico, in which 5 percent of people were killed by others. In Europe, even during the bloodiest periods — the 17th century and the first half of the 20th — deaths in war were around 3 percent. The data vindicates Hobbes’s basic insight, that without a state, life is likely to be “nasty, brutish and short.” In contrast, a state monopoly on the legitimate use of force reduces violence and makes everyone living under that monopoly better off than they would otherwise have been. Pinker calls this the “pacification process.”
It’s not only deaths in war, but murder, too, that is declining over the long term. Even those tribal peoples extolled by anthropologists as especially “gentle,” like the Semai of Malaysia, the Kung of the Kalahari and the Central Arctic Inuit, turn out to have murder rates that are, relative to population, comparable to those of Detroit. In Europe, your chance of being murdered is now less than one-tenth, and in some countries only one-fiftieth, of what it would have been if you had lived 500 years ago. American rates, too, have fallen steeply over the past two or three centuries. Pinker sees this decline as part of the “civilizing process,” a term he borrows from the sociologist Norbert Elias, who attributes it to the consolidation of the power of the state above feudal loyalties, and to the effect of the spread of commerce. (Consistent with this view, Pinker argues that at least part of the reason for the regional differences in American homicide rates is that people in the South are less likely to accept the state’s monopoly on force. Instead, a tradition of self-help justice and a “culture of honor” sanctions retaliation when one is insulted or mistreated. Statistics bear this out — the higher homicide rate in the South is due to quarrels that turn lethal, not to more killings during armed robberies — and experiments show that even today Southerners respond more strongly to insults than Northerners.)
During the Enlightenment, in 17th-and 18th-century Europe and countries under European influence, another important change occurred. People began to look askance at forms of violence that had previously been taken for granted: slavery, torture, despotism, dueling and extreme forms of cruel punishment. Voices even began to be raised against cruelty to animals. Pinker refers to this as the “humanitarian revolution.”
Against the background of Europe’s relatively peaceful period after 1815, the first half of the 20th century seems like a sharp drop into an unprecedented moral abyss. But in the 13th century, the brutal Mongol conquests caused the deaths of an estimated 40 million people — not so far from the 55 million who died in the Second World War — in a world with only one-seventh the population of the mid-20th century. The Mongols rounded up and massacred their victims in cold blood, just as the Nazis did, though they had only battle-axes instead of guns and gas chambers. A longer perspective enables us to see that the crimes of Hitler and Stalin were, sadly, less novel than we thought.
Since 1945, we have seen a new phenomenon known as the “long peace”: for 66 years now, the great powers, and developed nations in general, have not fought wars against one another. More recently, since the end of the cold war, a broader “new peace” appears to have taken hold. It is not, of course, an absolute peace, but there has been a decline in all kinds of organized conflicts, including civil wars, genocides, repression and terrorism. Pinker admits that followers of our news media will have particular difficulty in believing this, but as always, he produces statistics to back up his assertions.
The final trend Pinker discusses is the “rights revolution,” the revulsion against violence inflicted on ethnic minorities, women, children, homosexuals and animals that has developed over the past half-century. Pinker is not, of course, arguing that these movements have achieved their goals, but he reminds us how far we have come in a relatively short time from the days when lynchings were commonplace in the South; domestic violence was tolerated to such a degree that a 1950s ad could show a husband with his wife over his knees, spanking her for failing to buy the right brand of coffee; and Pinker, then a young research assistant working under the direction of a professor in an animal behavior lab, tortured a rat to death. (Pinker now considers this “the worst thing I have ever done.” In 1975 it wasn’t uncommon.)
What caused these beneficial trends? That question poses a special challenge to an author who has consistently argued against the view that humans are blank slates on which culture and education draws our character, good or evil. There has hardly been time for the changes to have a basis in genetic evolution. (Pinker considers this possibility, and dismisses it.) So don’t the trends that Pinker chronicles prove that our nature is more the product of our culture than our biology? That way of putting it assumes a simplistic nature-nurture dichotomy. In books like “How the Mind Works,” “The Blank Slate” and “The Stuff of Thought,” Pinker has argued that evolution shaped the basic design of our brain, and hence our cognitive and emotional faculties. This process has given us propensities to violence — our “inner demons” as well as “the better angels of our nature” (Abraham Lincoln’s words) — that incline us to be peaceful and cooperative. Our material circumstances, along with cultural inputs, determine whether the demons or the angels have the upper hand.
Other large-scale trends have paralleled the decline in violence and cruelty, but it is not easy to sort out cause and effect here. Are factors like better government, greater prosperity, health, education, trade and improvements in the status of women the cause or the effect of the decline in violence and cruelty? If we can find out, we may be able to preserve and extend the peaceful and better world in which we live. So in two chapters on human psychology, Pinker does his best to discover what has restrained our inner demons and unleashed our better angels, and then in a final chapter, draws his conclusions.
Those conclusions are not always what one might expect. Yes, as already noted, the state monopoly on force is important, and the spread of commerce creates incentives for cooperation and against violent conflict. The empowerment of women does, Pinker argues, exercise a pacifying influence, and the world would be more peaceful if women were in charge. But he also thinks that the invention of printing, and the development of a cosmopolitan “Republic of Letters” in the 17th and 18th centuries helped to spread ideas that led to the humanitarian revolution. That was pushed further in the 19th century by popular novels like “Uncle Tom’s Cabin” and “Oliver Twist” that, by encouraging readers to put themselves in the position of someone very different from themselves, expanded the sphere of our moral concern.
To readers familiar with the literature in evolutionary psychology and its tendency to denigrate the role reason plays in human behavior, the most striking aspect of Pinker’s account is that the last of his “better angels” is reason. Here he draws on a metaphor I used in my 1981 book “The Expanding Circle.” To indicate that reason can take us to places that we might not expect to reach, I wrote of an “escalator of reason” that can take us to a vantage point from which we see that our own interests are similar to, and from the point of view of the universe do not matter more than, the interests of others. Pinker quotes this passage, and then goes on to develop the argument much more thoroughly than I ever did. (Disclosure: Pinker wrote an endorsement for a recent reissue of “The Expanding Circle.”)
Pinker’s claim that reason is an important factor in the trends he has described relies in part on the “Flynn effect” — the remarkable finding by the philosopher James Flynn that ever since I.Q. tests were first administered, the scores achieved by those taking the test have been rising. The average I.Q. is, by definition, 100; but to achieve that result, raw test scores have to be standardized. If the average teenager today could go back in time and take an I.Q. test from 1910, he or she would have an I.Q. of 130, which would be better than 98 percent of those taking the test then. Nor is it easy to attribute this rise to improved education, because the aspects of the tests on which scores have risen most do not require a good vocabulary or even mathematical ability, but instead test powers of abstract reasoning. One theory is that we have gotten better at I.Q. tests because we live in a more symbol-rich environment. Flynn himself thinks that the spread of the scientific mode of reasoning has played a role.
Pinker argues that enhanced powers of reasoning give us the ability to detach ourselves from our immediate experience and from our personal or parochial perspective, and frame our ideas in more abstract, universal terms. This in turn leads to better moral commitments, including avoiding violence. It is just this kind of reasoning ability that has improved during the 20th century. He therefore suggests that the 20th century has seen a “moral Flynn effect, in which an accelerating escalator of reason carried us away from impulses that lead to violence” and that this lies behind the long peace, the new peace, and the rights revolution. Among the wide range of evidence he produces in support of that argument is the tidbit that since 1946, there has been a negative correlation between an American president’s I.Q. and the number of battle deaths in wars involving the United States.
Reason also, Pinker suggests, moves us away from forms of morality more likely to lead to violence, and toward moral advances that, while not eschewing the use of force altogether, restrict it to the uses necessary to improve social welfare, like utilitarian reforms of the savage punishments given to criminals in earlier times. For reason does, Pinker holds, point to a particular kind of morality. We prefer life to death, and happiness to suffering, and we understand that we live in a world in which others can make a difference to whether we live well or die miserably. Therefore we will want to tell others that they should not hurt us, and in doing so we commit ourselves to the idea that we should not hurt them. (Pinker quotes a famous sentence from the 18th-century philosopher William Godwin: “What magic is there in the pronoun ‘my’ that should justify us in overturning the decisions of impartial truth?”) That morality can be grounded in some commitment to treating others as we would like them to treat us is an ancient idea, expressed in the golden rule and in similar thoughts in the moral traditions of many other civilizations, but Pinker is surely right to say that the escalator of reason leads us to it. It is this kind of moral thinking, Pinker points out, that helps us escape traps like the Cuban missile crisis, which, if the fate of the world had been in the hands of leaders under the sway of a different kind of morality — one dominated by ideas of honor and the importance of not backing down — might have been the end of the human story. Fortunately Kennedy and Khrushchev understood the trap they were in and did what was necessary to avoid disaster.
“The Better Angels of Our Nature” is a supremely important book. To have command of so much research, spread across so many different fields, is a masterly achievement. Pinker convincingly demonstrates that there has been a dramatic decline in violence, and he is persuasive about the causes of that decline. But what of the future? Our improved understanding of violence, of which Pinker’s book is an example, can be a valuable tool to maintain peace and reduce crime, but other factors are in play. Pinker is an optimist, but he knows that there is no guarantee that the trends he has documented will continue. Faced with suggestions that the present relatively peaceful period is going to be blown apart by a “clash of civilizations” with Islam, by nuclear terrorism, by war with Iran or wars resulting from climate change, he gives reasons for thinking that we have a good chance of avoiding such conflicts, but no more than a good chance. If he had been able to see, before his book went to press, a study published in Nature as recently as August of this year, he might have been less sanguine about maintaining peace despite widespread climate change. Solomon Hsiang and colleagues at Columbia University used data from the past half-century to show that in tropical regions, the risk of a new civil conflict doubles during El Niño years (when temperatures are hotter than usual and there is less rainfall). If that finding is correct, then a warming world could mean the end of the relatively peaceful era in which we are now living.
Peter Singer is professor of bioethics at Princeton University. His books include “Animal Liberation,” “Practical Ethics,” “The Expanding Circle” and “The Life You Can Save.”