A Troublesome Inheritance: Genes, Race and Human History

by Nicholas Wade

  “The surname evidence confirms a permanent selection in pre-industrial England for the genes of the economically successful, and against the genes of the poor and the criminal,” Clark concludes. “Their extra reproductive success had a permanent impact on the genetic composition of the later population.” 9

  Clark’s data provide substantial evidence that the English population responded genetically to the harsh stresses of a Malthusian regime and that the shifts in its social behavior from 1200 to 1800 were shaped by natural selection. The burden of proof is surely shifted to those who might wish to assert that the English population was miraculously exempt from the very forces of natural selection whose existence it had suggested to Darwin.

  Evolutionary Changes in China

  In China, no equivalent data exist to track changes in social behavior through the generations. But the population clearly fell under intense Malthusian pressure as population density increased. Between 1350 and 1850, the population expanded from 65 million to 430 million. The only checks on growth were the Malthusian constraints of high infant mortality and of malnutrition, which lowered fertility. Female infanticide was a principal means of birth control, with the result that many men could never find wives.

  The harshness of the struggle was made no easier by Chinese inheritance practices, which left an estate to be divided equally between the owner’s sons. A slightly wealthy peasant family might revert to poverty because each son had to start with a much smaller plot of land. “Each generation, a few who were lucky or able might rise, but a vast multitude always fell, and those families near the bottom simply disappeared from the world,” writes the essayist Ron Unz.10

  A successful family could maintain its economic position over time, Unz writes, “only if in each generation large amounts of additional wealth were extracted from their land and their neighbors through high intelligence, sharp business sense, hard work and great diligence.”

  Though many poor families perished, there was also movement in the other direction. Within its authoritarian structure, Chinese society was reasonably meritocratic. The examinations for the mandarinate were in principle open to any adult male. Records available from the Ming (1368–1644) and Qing (1644–1912) dynasties show that more than 30% of those who held the highest mandarin rank came from commoner families.

  What effect did these forces have on shaping the genetics and social behavior of the Chinese population? There was evidently high selective pressure for survival skills, given that the poorest individuals in each generation were eliminated. Those who worked hard, had the right social skills and made intelligent choices could make their way from the bottom of society to the top in several generations. With a high official’s wealth, they could raise more children, amplifying their successful genes before their descendants sank down in status.

  Though the Mandarin class might seem at first too small to have exerted any genetic impact on a large population, the examination system operated over many generations and in a population initially much smaller than that of today. The system, though in rudimentary form, was first instituted by the emperor Wu in 124 BC. Over many generations, it would have disseminated upper-class values throughout society as the more numerous children of the well off descended through the social strata.

  The examinees were awarded no marks for originality, however. The exams were based on rote memorization of the Chinese classics and formalized commentaries on the text. “It is obvious that such a system of universal examinations, based on examination questions created by a board of senior bureaucrats, established an extraordinary uniformity of attitude and opinion,” writes the sociologist of science Toby Huff.11 The probable effect of the system was to select for excellent memory, high intelligence and unwavering conformity.

  At each cycle, the Chinese population became enriched in survival skills. At the same time, authoritarian regimes ruthlessly repressed dissent, just as they do today. This particular set of pressures has borne down on the population for 2,000 years, or some 80 generations, with the evolutionary outcome that has made the Chinese a distinctive population. High intelligence may be one of the behaviors shaped by China’s Malthusian regime—Chinese score above Europeans on IQ tests (though so do Koreans and Japanese). Another may be conformity.

  The Long Arc of Domestication

  The bourgeoisification of the English population between 1200 and 1800 is a minuscule slice, one that just happens to be documentable, of a long evolutionary process that began in the mists of the last ice age. That process was the civilizing of our remote ancestors, as roving bands of unruly foragers were transformed into people peaceable enough to settle down together.

  The process can be called a domestication because, to judge from the evidence of human fossil remains, it seems to parallel the domestication of animal species by the first farmers. As already noted, human skulls and skeletons from about 40,000 years ago become lighter and less robust, as if their owners were no longer fighting one another all the time and could afford more lightly built bone structures.

  This lightening of the bone, a genetically based process, is seen in the fossil remains of species like pigs and cattle as they were domesticated from their wild forebears. In people this process, called gracilization, proceeded independently in each of the world’s populations, according to the physical anthropologist Marta Mirazón Lahr.12 All populations followed this trend save for two at the extremities of the human diaspora, the Fuegians at the tip of South America and the aborigines of Australia. Gracilization of the skull is most pronounced in sub-Saharan Africans and East Asians, with Europeans retaining considerable robustness.13

  In domestic animals, gracilization is one of the side effects of the taming process. The general process is known as pedomorphic evolution, meaning a trend toward the juvenile form. Thus a dog’s skull and teeth are smaller than those of a wolf, and the shape of the skull resembles that of a juvenile wolf.

  The gracilization of human skulls, the primatologist Richard Wrangham has noted, looks just like the gracilization seen in domestic animals. If this is a side effect of domestication in people too, then exactly who was doing the taming? The obvious answer, Wrangham suggests, is that people must have been taming themselves, by killing or ostracizing individuals who were immoderately violent. Moreover, this ancient process, in his view, is still in motion: “I think that current evidence is that we’re in the middle of an evolutionary event in which tooth size is falling, jaw size is falling, and it’s quite reasonable to imagine that we’re continuing to tame ourselves,” Wrangham says.14 A likely signal of the fact that people today are so much tamer than their forebears is that their shrinking jaws don’t now have room for all the teeth that are programmed into them, so the wisdom teeth must often be removed.

  Another insight into the human taming process, from a quite different perspective, has been developed by the sociologist Norbert Elias. Despite working in the shadow of the impending Second World War, Elias was fascinated by the decline of violence in Europe since the Middle Ages. He was concerned not with wars between states but with violence in everyday life. He attributed the decline in personal violence to a long-term psychological change in the population, that of the growth of self-restraint.

  A starting point for Elias’s analysis was medieval treatises on polite manners such as the book On Civility in Children by the Renaissance scholar Erasmus. In the 16th century, Europeans’ everyday social behavior was beyond gross. It was a social world in which books on good etiquette had to advise people not to blow their noses on the tablecloth nor to snort or smack their lips while eating. People ate with their hands, the fork being a strange luxury. They blew their noses without the aid of a handkerchief or tissues. They performed many bodily functions in public. Their sensibility toward the pain of others was minimal. Public executions were common, often preceded by torture or dismemberment. People behaved with unthinking cruelty toward animals.

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sp; A famous midsummer day festivity in 16th century Paris was to burn alive a dozen cats. The king and queen were usually present, and the king or the dauphin would light a pyre. The cats were then tumbled into the flames from an overhead basket, and the crowd reveled in their cries.

  “Certainly this is not really a worse spectacle than the burning of heretics, or the torturings and public executions of every kind,” Elias writes. “It only appears worse because the joy in torturing living creatures shows itself so nakedly and purposelessly, without any excuse before reason. The revulsion aroused in us by the mere report of the institution, a reaction which must be taken as ‘normal’ for the present-day standard of affect control, demonstrates once again the long term change of personality structure.” 15

  Elias argued that between medieval and modern times, a societywide shift has taken place toward greater sensibility and more delicate manners. Underlying this civilizing process, he believed, was a psychological shift toward greater self-awareness and self-control. He attributed this change in personality structure in part to the monopolization of force by the state, meaning that individuals needed less to resort to violence in self-defense, and in part to the greater interconnectedness of urban societies, which required individuals increasingly to attune their conduct to that of others and hence to moderate their behavior.

  Elias was unable to put numbers on his argument, but these are supplied in profusion in a voluminous survey on violence over the ages by the psychologist Steven Pinker. Contrary to widespread belief that the 20th century was more violent than any other, Pinker establishes that both personal violence and deaths in warfare have been in steady decline for as long as records can tell.

  In terms of violence between states, the percentage of people who died in warfare is far higher in pre-state societies, to judge by evidence from archaeology and anthropology, than in the states that succeeded them. The death rate in pre-state societies averages 15% but had fallen to a mere 3% in the first half of the 20th century, a period that includes the two world wars.16

  Personal violence too has been in steady decline. Between 1200 and 2000, homicide rates per 100,000 people fell from 90 or so to just over one in five European countries.17 Parallel to the fall in violence is evidence for a general increase in empathy toward the pain of others. People stopped burning women for suspicion of witchcraft; in England the last witch was burned in 1716. Judicial torture was gradually abolished in Europe from 1625 onward.18 Finally, empathy compelled the abolition of slavery.

  Pinker agrees with Elias that the principal drivers of the civilizing process were the increasing monopoly of force by the state, which reduced the need for interpersonal violence, and the greater levels of interaction with others that were brought about by urbanization and commerce.

  The next question of interest is whether the long behavioral shift toward more restrained behavior had a genetic basis. The gracilization of human skulls prior to 15,000 years ago almost certainly did, and Clark makes a strong case that the molding of the English population from rough peasants into industrious citizenry between 1200 and 1800 AD was a continuation of this evolutionary process. On the basis of Pinker’s vast compilation of evidence, natural selection seems to have acted incessantly to soften the human temperament, from the earliest times until the most recent date for which there is meaningful data.

  This is the conclusion that Pinker signals strongly to his readers. He notes that mice can be bred to be more aggressive in just five generations, evidence that the reverse process could occur just as speedily. He describes the human genes, such as the violence-promoting MAO-A mutation mentioned in chapter 3, that could easily be modulated so as to reduce aggressiveness. He mentions that violence is quite heritable, on the evidence from studies of twins, and so must have a genetic basis. He states that “nothing rules out the possibility that human populations have undergone some degree of biological evolution in recent millennia, or even centuries, long after races, ethnic groups, and nations diverged.” 19

  But at the last moment, Pinker veers away from the conclusion, which he has so strongly pointed to, that human populations have become less violent in the past few thousand years because of the continuation of the long evolutionary trend toward less violence. He mentions that evolutionary psychologists, of whom he is one, have always held that the human mind is adapted to the conditions of 10,000 years ago and hasn’t changed since.

  But since many other traits have evolved more recently than that, why should human behavior be any exception? Well, says Pinker, it would be terribly inconvenient politically if this were so. “It could have the incendiary implication that aboriginal and immigrant populations are less biologically adapted to the demands of modern life than populations that have lived in literate state societies for millennia.” 20

  Whether or not a thesis might be politically incendiary should have no bearing on the estimate of its scientific validity. That Pinker would raise this issue in a last minute diversion of a sustained scientific argument is an explicit acknowledgment to the reader of the political dangers that researchers, even ones of his stature and independence, would face in pursuing the truth too far.

  Turning on a dime, Pinker then contends that there is no evidence that the decline in violence over the past 10,000 years is an evolutionary change. To reach this official conclusion, he is obliged to challenge Clark’s evidence that there was indeed such a change. But he does so with an array of arguments that seem less than decisive. Clark’s proposed mechanism for the spread of middle-class values is based on the fact that the rich, until recently, had more surviving children than did the poor. Pinker objects that this was true of every society, not just the one that later blasted off into the Industrial Revolution. But this is exactly what Clark’s thesis requires to happen in order for the Industrial Revolution to spread to other countries. The mechanism was a pre-condition for the Industrial Revolution wherever it occurred. The specific trigger in England, which explains why it started there rather than in any of the other possible birthplaces in Europe and East Asia, was a sudden boom in the English population.

  Pinker notes that countries without a recent history of selection for middle-class values, like China and Japan, can attain spectacular rates of economic growth. But both these countries had long been agrarian economies operating, like England, under Malthusian constraints that favored survival of those who worked hard and saved hard. It was only institutional barriers that delayed these countries’ transition to modern economies, and as soon as the barriers were removed, both economies soared. Last, Pinker cites Clark’s failure to prove that the English are innately less violent than the inhabitants of countries that have not enjoyed an industrial revolution. This seems an unfair criticism, given that the genes underlying violence are for the most part unknown. Nonetheless, the homicide rate in the United States, Europe, China and Japan is less than 2 per 100,000 people, whereas in most African countries south of the Sahara, it exceeds 10 per 100,000, a difference that does not prove but surely allows room for a genetic contribution to greater violence in the less developed world.21

  The ultimate proof of Clark’s thesis would be discovery of the new alleles that have mediated the social behavior required for Europeans and East Asians to make the transition to modern economies. But there are probably many such genes, each with a small and barely detectible effect, so it may take decades before any come to light.

  Meanwhile, his thesis of an evolutionary change provides a powerful explanatory scheme for understanding modern societies, especially when combined with the understanding of political institutions developed by Fukuyama. The countries that have not completed the transition to modern states retain the default state of human political systems, namely that of tribalism.

  Tribal Societies

  Africa and much of the Middle East remain largely tribal societies. Tribalism has a bleak reputation because tribal organization is incompatible with that of
a modern state. That aside, it is an amazingly ingenious way of securing a rough degree of social order without a government, courts, police force or law books.

  In the Arab Middle East, tribalism rests on the idea of group protection. When government does not provide the legal system in which a citizen may seek and secure justice, people rely instead on their relatives. Someone who is wronged will seek his kin’s backing against the individual who wronged him. The kin group may be just his family, his extended family or his whole tribe, depending on how far the dispute escalates. A similarly sized group forms around the man he accuses. Hostilities may break out, but the two opposing groups have many inducements to settle, being of generally equal numbers and with each having many members with relatives in the other group. The individual’s rights are thus protected, but by the threat of force, not by appeal to law or any formal judicial process.

  What makes the system work is the duty felt by each individual to support his group against others, no matter what the personal cost. Failure to support one’s family or tribe in a standoff leads to dishonor and means the group’s future support of one’s own cause may be forfeited.

  The tribal system is egalitarian, individualistic and secures redress of wrongs with a minimum of bureaucracy. Despite these outstanding merits, it has grave flaws. It depends on force and group loyalty, not on law. Children are taught from the earliest age that their group is always right and must be supported no matter what. Adults follow the ancient rule: support the nearest group of relatives against the more distant groups. In terms of national politics, the spirit of tribalism leads to “monopoly of power, ruthless oppression of opponents, and accumulation of benefits,” writes Philip Salzman, an anthropologist at McGill University who studies nomadic tribes. “In short, it is a recipe for despotism, for tyranny.” 22