The Better Angels of Our Nature: Why Violence Has Declined

  We tend to be blasé about moral progress as well, but historians who take the long view have also marveled at the moral advances of the past six decades. As we saw, the Long Peace has had the world’s most distinguished military historians shaking their heads in disbelief. The Rights Revolutions too have given us ideals that educated people today take for granted but that are virtually unprecedented in human history, such as that people of all races and creeds have equal rights, that women should be free from all forms of coercion, that children should never, ever be spanked, that students should be protected from bullying, and that there’s nothing wrong with being gay. I don’t find it at all implausible that these are gifts, in part, of a refined and widening application of reason.

  The other half of the sanity check is to ask whether our recent ancestors can really be considered morally retarded. The answer, I am prepared to argue, is yes. Though they were surely decent people with perfectly functioning brains, the collective moral sophistication of the culture in which they lived was as primitive by modern standards as their mineral spas and patent medicines are by the medical standards of today. Many of their beliefs can be considered not just monstrous but, in a very real sense, stupid. They would not stand up to intellectual scrutiny as being consistent with other values they claimed to hold, and they persisted only because the narrower intellectual spotlight of the day was not routinely shone on them.

  Lest you think this judgment a slander on our forebears, consider some of the convictions that were common in the decades before the effects of rising abstract intelligence began to accumulate. A century ago dozens of great writers and artists extolled the beauty and nobility of war, and eagerly looked forward to World War I. One “progressive” president, Theodore Roosevelt, wrote that the decimation of Native Americans was necessary to prevent the continent from becoming a “game preserve for squalid savages,” and that in nine out of ten cases, “the only good Indians are the dead Indians.”257 Another, Woodrow Wilson, was a white supremacist who kept black students out of Princeton when he was president of the university, praised the Ku Klux Klan, cleansed the federal government of black employees, and said of ethnic immigrants, “Any man who carries a hyphen about with him carries a dagger that he is ready to plunge into the vitals of this Republic whenever he gets ready.” 258 A third, Franklin Roosevelt, drove a hundred thousand American citizens into concentration camps because they were of the same race as the Japanese enemy.

  On the other side of the Atlantic, the young Winston Churchill wrote of taking part in “a lot of jolly little wars against barbarous peoples” in the British Empire. In one of those jolly little wars, he wrote, “we proceeded systematically, village by village, and we destroyed the houses, filled up the wells, blew down the towers, cut down the shady trees, burned the crops and broke the reservoirs in punitive devastation.” Churchill defended these atrocities on the grounds that “the Aryan stock is bound to triumph,” and he said he was “strongly in favor of using poisoned gas against uncivilized tribes.” He blamed the people of India for a famine caused by British mismanagement because they kept “breeding like rabbits,” adding, “I hate Indians. They are a beastly people with a beastly religion.” 259

  Today we are stunned by the compartmentalized morality of these men, who in many ways were enlightened and humane when it came to their own race. Yet they never took the mental leap that would have encouraged them to treat the people of other races with the same consideration. I still remember gentle lessons from my mother when my sister and I were children in the early 1960s, lessons that millions of children have received in the decades since: “There are bad Negroes and there are good Negroes, just like there are bad white people and good white people. You can’t tell whether a person is good or bad by looking at the color of his skin.” “Yes, the things those people do look funny to us. But the things we do look funny to them.” Such lessons are not indoctrination but guided reasoning, leading children to conclusions they can accept by their own lights. Surely this reasoning was within the ken of the neural hardware of the great statesmen of a century ago. The difference is that today’s children have been encouraged to take these cognitive leaps, and the resulting understanding has become second nature. Shorthand abstractions like freedom of speech, tolerance, human rights, civil rights, democracy, peaceful coexistence, and nonviolence (and their antitheses such as racism, genocide, totalitarianism, and war crimes) spread outward from their origins in abstract political discourse and became a part of everyone’s mental tool kit. The advances can fairly be called a gain in intelligence, not completely different from the ones that drove scores in abstract reasoning upward.

  Moral stupidity was not confined to the policies of leaders; it was written into the law of the land. Within the lifetimes of many readers of this book, the races in much of the country were forcibly segregated, women could not serve on juries in rape trials because they would be embarrassed by the testimony, homosexuality was a felony crime, and men were allowed to rape their wives, confine them to the house, and sometimes kill them and their adulterous lovers. And if you think that today’s congressional proceedings are dumb, consider this 1876 testimony from a lawyer representing the city of San Francisco in hearings on the rights of Chinese immigrants:In relation to [the Chinese] religion, it is not our religion. That is enough to say about it; because if ours is right theirs must necessarily be wrong. [Question: What is our religion?] Ours is a belief in the existence of a Divine Providence that holds in its hands the destinies of nations. The Divine Wisdom has said that He would divide the country and the world as the heritage of five great families; that to the blacks He would give Africa; to the whites He would give Europe; to the red man He would give America, and Asia He would give to the yellow races. He inspires us with the determination not only to have preserved our own inheritance, but to have stolen from the red man America; and it is settled now that the Saxon, American or European groups of families, the white race, is to have the inheritance of Europe and of America and that the yellow races of China are to be confined to what God Almighty originally gave them; and as they are not a favorite people they are not to be permitted to steal from us what we robbed the American savage of.260

  Nor was it just lawmakers who were intellectually challenged when it came to moral reasoning. I mentioned in chapter 6 that in the decades surrounding the turn of the 20th century, many literary intellectuals (including Yeats, Shaw, Flaubert, Wells, Lawrence, Woolf, Bell, and Eliot) expressed a contempt for the masses that bordered on the genocidal.261 Many others would come to support fascism, Nazism, and Stalinism.262 John Carey quotes from an essay by Eliot in which the poet comments on the spiritual superiority of the great artist: “It is better, in a paradoxical way, to do evil than to do nothing: at least we exist.” Carey comments from a later era: “This appalling sentence leaves out of account, we notice, the effect of evil on its victims.” 263

  The idea that the changes behind the Flynn Effect have also expanded the moral circle passes a sanity check, but that does not mean it is true. To show that rising intelligence has led to less violence, at the very least one needs to establish this intermediate link: that on average, and all else being equal, people with more sophisticated reasoning abilities (as assessed by IQ or other measures) are more cooperative, have larger moral circles, and are less sympathetic to violence. Better still, one would like to show that entire societies of better-reasoning individuals adopt policies that are less conducive to violence. If smarter people and smarter societies are less likely to be violent, then perhaps the recent rise in intelligence can help explain the recent decline of violence.

  Before we examine the evidence for this hypothesis, let me clarify what it is not. The kind of reasoning relevant to moral progress is not general intelligence in the sense of raw brainpower, but the cultivation of abstract reasoning, the aspect of intelligence that has been pulled upward by the Flynn Effect. The two are highly correlated, so measures of IQ will, in general, track a
bstract reasoning, but it’s the latter that is relevant to the escalator hypothesis. For the same reason, the specific differences in reasoning that I will focus on are not necessarily heritable (even though general intelligence is highly heritable), and I will stick with the assumption that all differences among groups are environmental in origin.

  It’s also important to note that the escalator hypothesis is about the influence of rationality—the level of abstract reasoning in a society—and not about the influence of intellectuals. Intellectuals, in the words of the writer Eric Hoffer, “cannot operate at room temperature.” 264 They are excited by daring opinions, clever theories, sweeping ideologies, and utopian visions of the kind that caused so much trouble during 20th century. The kind of reason that expands moral sensibilities comes not from grand intellectual “systems” but from the exercise of logic, clarity, objectivity, and proportionality. These habits of mind are distributed unevenly across the population at any time, but the Flynn Effect lifts all the boats, and so we might expect to see a tide of mini- and micro-enlightenments across elites and ordinary citizens alike.

  Let me present seven links, varying in directness, between reasoning ability and peaceable values.

  Intelligence and Violent Crime. The first link is the most direct: smarter people commit fewer violent crimes, and they are the victims of fewer violent crimes, holding socioeconomic status and other variables constant.265 We have no way to pinpoint the causal arrow—whether smarter people realize that violence is wrong or pointless, whether they exercise more self-control, or whether they keep themselves out of situations in which violence takes place. But all else being equal (setting aside, for example, the oscillations in crime from the 1960s through the 1980s), as people get smarter, there should be less violence.

  Intelligence and Cooperation. At the other end of the abstractness scale, we can consider the purest model of how abstract reasoning might undermine the temptations of violence, the Prisoner’s Dilemma. In his popular Scientific American column, the computer scientist Douglas Hofstadter once agonized over the fact that the seemingly rational response in a one-shot Prisoner’s Dilemma was to defect.266 You cannot trust the other player to cooperate, because he has no grounds for trusting you, and cooperating while he defects will bring you the worst outcome. Hofstadter’s agony came from the observation that if both sides looked down on their dilemma from a single Olympian vantage point, stepping out of their parochial stations, they should both deduce that the best outcome is for both to cooperate. If each has confidence that the other realizes that, and that the other realizes that he or she realizes it, ad infinitum, both should cooperate and reap the benefits. Hofstadter envisioned a superrationality in which both sides were certain of the other’s rationality, and certain that the other was certain of theirs, and so on, though he wistfully acknowledged that it was not easy to see how to get people to be superrational.

  Can higher intelligence at least nudge people in the direction of superrationality? That is, are better reasoners likely to reflect on the fact that mutual cooperation leads to the best joint outcome, assume that the other guy is reflecting on it as well, and profit from the resulting simultaneous leap of trust? No one has given people of different levels of intelligence a true one-shot Prisoner’s Dilemma, but a recent study came close by using a sequential one-shot Prisoner’s Dilemma, in which the second player acts only after seeing the first player’s move. The economist Stephen Burks and his collaborators gave a thousand trainee truck drivers a Matrices IQ test and a Prisoner’s Dilemma, using money for the offers and payoffs.267 The smarter truckers were more likely to cooperate on the first move, even after controlling for age, race, gender, schooling, and income. The investigators also looked at the response of the second player to the first player’s move. This response has nothing to do with superrationality, but it does reflect a willingness to cooperate in response to the other player’s cooperation in such a way that both players would benefit if the game were iterated. Smarter truckers, it turned out, were more likely to respond to cooperation with cooperation, and to defection with defection.

  The economist Garrett Jones connected intelligence to the Prisoner’s Dilemma by a different route. He scoured the literature for all the Iterated Prisoner’s Dilemma experiments that had been conducted in colleges and universities from 1959 to 2003.268 Across thirty-six experiments involving thousands of participants, he found that the higher a school’s mean SAT score (which is strongly correlated with mean IQ), the more its students cooperated. Two very different studies, then, agree that intelligence enhances mutual cooperation in the quintessential situation in which its benefits can be foreseen. A society that gets smarter, then, may be a society that becomes more cooperative.

  Intelligence and Liberalism. Now we get to a finding that sounds more tendentious than it is: smarter people are more liberal. The statement will make conservatives see red, not just because it seems to impugn their intelligence but because they can legitimately complain that many social scientists (who are overwhelmingly liberal or leftist) use their research to take cheap shots at the right, studying conservatism as if it were a mental defect. (Tetlock and Haidt have both called attention to this politicization.)269 So before turning to the evidence that links intelligence to liberalism, let me qualify the connection.

  For one thing, since intelligence is correlated with social class, any correlation with liberalism, if not statistically controlled, could simply reflect the political prejudices of the upper middle classes. But the key qualification is that the escalator of reason predicts only that intelligence should be correlated with classical liberalism, which values the autonomy and well-being of individuals over the constraints of tribe, authority, and tradition. Intelligence is expected to correlate with classical liberalism because classical liberalism is itself a consequence of the interchangeability of perspectives that is inherent to reason itself. Intelligence need not correlate with other ideologies that get lumped into contemporary left-of-center political coalitions, such as populism, socialism, political correctness, identity politics, and the Green movement. Indeed, classical liberalism is sometimes congenial to the libertarian and antipolitical-correctness factions in today’s right-of-center coalitions. But on the whole, Haidt’s surveys show that it is the people who identify their politics with the word liberal who are more likely to emphasize fairness and autonomy, the cardinal virtues of classical liberalism, over community, authority, and purity.270 And as we saw in chapter 7, the self-described liberals are ahead of the curve on issues of personal autonomy, and the positions they pioneered decades ago have been increasingly accepted by conservatives today.

  The psychologist Satoshi Kanazawa has analyzed two large American datasets and found that in both, intelligence correlates with the respondents’ political liberalism, holding age, sex, race, education, earnings, and religion statistically constant.271 Among more than twenty thousand young adults who had participated in the National Longitudinal Study of Adolescent Health, average IQ increased steadily from those who identified themselves as “very conservative” (94.8) to those who identified themselves as “very liberal” (106.4). The General Social Survey shows a similar correlation, while also containing a hint that intelligence tracks classical liberalism more closely than left-liberalism. The smarter respondents in the survey were less likely to agree with the statement that the government has a responsibility to redistribute income from the rich to the poor (leftist but not classically liberal), while being more likely to agree that the government should help black Americans to compensate for the historical discrimination against them (a formulation of a liberal position which is specifically motivated by the value of fairness).

  A better case that intelligence causes, rather than merely correlates with, classical liberal attitudes comes from analyses by the psychologist Ian Deary and his colleagues on a dataset that includes every child born in Britain in a particular week in 1970. The title of their paper says it all: “Bright child
ren become enlightened adults.” 272 By “enlightened” they mean the mindset of the Enlightenment, which they define, following the Concise Oxford Dictionary, as “a philosophy emphasizing reason and individualism rather than tradition.” They found that children’s IQ at the age of ten (including tests of abstract reasoning) predicted their endorsement of antiracist, socially liberal, and proworking-women attitudes at the age of thirty, holding constant their education, their social class, and their parents’ social class. The socioeconomic controls, together with the twenty-year lag between the measurement of intelligence and the measurement of attitudes, make a prima facie case that the causal arrow goes from intelligence to classical liberalism. A second analysis discovered that brighter ten-year-olds were more likely to vote when they grew up, and more likely to vote for the Liberal Democrats (a center-left/libertarian coalition) or the Greens, and less likely to vote for nationalist and antiimmigrant parties. Again, there is a suggestion that intelligence leads to classical rather than left-liberalism: when social class was controlled, the IQ-Green correlation vanished, but the IQ–Lib Dem correlation survived.