Even many scientists are perfectly content with the radicals’ social constructionism, not so much because they agree with it but because they are preoccupied in their labs and need picketers outside their window like they need another hole in the head. As the anthropologist John Tooby and the psychologist Leda Cosmides note, the dogma that biology is intrinsically disconnected from the human social order offers scientists “safe conduct across the politicized minefield of modern academic life.”55 As we shall see, even today people who challenge the Blank Slate or the Noble Savage are still sometimes silenced by demonstrators or denounced as Nazis. Even when such attacks are sporadic, they create an atmosphere of intimidation that distorts scholarship far and wide.

  But the intellectual climate is showing signs of change. Ideas about human nature, while still anathema to some academics and pundits, are beginning to get a hearing. Scientists, artists, scholars in the humanities, legal theorists, and thoughtful laypeople have expressed a thirst for the new insights about the mind that have been coming out of the biological and cognitive sciences. And the radical science movement, for all its rhetorical success, has turned out to be an empirical wasteland. Twenty-five years of data have not been kind to its predictions. Chimpanzees are not peaceful vegetarians, as Montagu claimed, nor is the heritability of intelligence indistinguishable from zero, IQ a “reification” unrelated to the brain, personality and social behavior without any genetic basis, gender differences a product only of “psychocultural expectations,” or the number of murderous clans equal to the number of pacific bands.56 Today the idea of guiding scientific research by “a conscious application of Marxist philosophy” is just embarrassing, and as the evolutionary psychologist Martin Daly pointed out, “Sufficient research to fill a first issue of Dialectical Biology has yet to materialize.”57

  In contrast, sociobiology did not, as Sahlins had predicted, turn out to be a passing fad. The title of Alcock’s 2001 book The Triumph of Sociobiology says it all: in the study of animal behavior, no one even talks about “sociobiology” or “selfish genes” anymore, because the ideas are part and parcel of the science.58 In the study of humans, there are major spheres of human experience—beauty, motherhood, kinship, morality, cooperation, sexuality, violence—in which evolutionary psychology provides the only coherent theory and has spawned vibrant new areas of empirical research.59 Behavioral genetics has revivified the study of personality and will only expand with the application of knowledge from the Human Genome Project.60 Cognitive neuroscience will not shrink from applying its new tools to every aspect of mind and behavior, including the emotionally and politically charged ones.

  The question is not whether human nature will increasingly be explained by the sciences of mind, brain, genes, and evolution, but what we are going to do with the knowledge. What in fact are the implications for our ideals of equality, progress, responsibility, and the worth of the person? The opponents of the sciences of human nature from the left and the right are correct about one thing: these are vital questions. But that is all the more reason that they be confronted not with fear and loathing but with reason. That is the goal of the next part of the book.

  PART III

  HUMAN NATURE WITH A HUMAN FACE

  When Galileo attracted the unwanted attention of the Inquisition in 1633, more was at stake than issues in astronomy. By stating that the Earth revolved around the sun rather than vice versa, Galileo was contradicting the literal truth of the Bible, such as the passage in which Joshua issued the successful command “Sun, stand thou still.” Worse, he was challenging a theory of the moral order of the universe.

  According to the theory, developed in medieval times, the sphere of the moon divided the universe into an unchanging perfection in the heavens above and a corrupt degeneration in the Earth below (hence Samuel Johnson’s disclaimer that he could not “change sublunary nature”). Surrounding the moon were spheres for the inner planets, the sun, the outer planets, and the fixed stars, each cranked by a higher angel. And surrounding them all were the heavens, home to God. Contained within the sphere of the moon, and thus a little lower than the angels, were human souls, and then, in descending order, human bodies, animals (in the order beasts, birds, fish, insects), then plants, minerals, the inanimate elements, nine layers of devils, and finally, at the center of the Earth, Lucifer in hell. The universe was thus arranged in a hierarchy, a Great Chain of Being.

  The Great Chain was thick with moral implications. Our home, it was thought, lay at the center of the universe, reflecting the importance of our existence and behavior. People lived their lives in their proper station (king, duke, or peasant), and after death their souls rose to a higher place or sank to a lower one. Everyone had to be mindful that the human abode was a humble place in the scheme of things and that they must look up to catch a glimpse of heavenly perfection. And in a world that seemed always to teeter on the brink of famine and barbarism, the Great Chain offered the comfort of knowing that the nature of things was orderly. If the planets wandered from their spheres, chaos would break out, because everything was connected in the cosmic order. As Alexander Pope wrote, “From Nature’s chain whatever link you strike, / Tenth, or ten thousandth, breaks the chain alike.”1

  None of this escaped Galileo as he was pounding away at his link. He knew that he could not simply argue on empirical grounds that the division between a corrupt Earth and the unchanging heavens was falsified by sunspots, novas, and moons drifting across Jupiter. He also argued that the moral trappings of the geocentric theory were as dubious as its empirical claims, so if the theory turned out to be false, no one would be the worse. Here is Galileo’s alter ego in Dialogue Concerning the Two Chief World Systems, wondering what is so great about being invariant and inalterable:

  For my part I consider the earth very noble and admirable precisely because of the diverse alterations, changes, generations, etc. that occur in it incessantly. If, not being subject to any changes, it were a vast desert of sand or mountain of jasper, or if at the time of the flood the waters which covered it had frozen, and it had remained an enormous globe of ice where nothing was ever born or ever altered or changed, I should deem it a useless lump in the universe, devoid of activity and, in a word, superfluous and essentially nonexistent. This is exactly the difference between a living animal and a dead one; and I say the same of the moon, of Jupiter, and of all other world globes.

  … Those who so greatly exalt incorruptibility, inalterability, et cetera, are reduced to talking this way, I believe, by their great desire to go on living, and by the terror they have of death. They do not reflect that if men were immortal, they themselves would never have come into the world. Such men really deserve to encounter a Medusa’s head which would transmute them into statues of jasper or diamond, and thus make them more perfect than they are.2

  Today we see things Galileo’s way. It’s hard for us to imagine why the three-dimensional arrangement of rock and gas in space should have anything to do with right and wrong or with the meaning and purpose of our lives. The moral sensibilities of Galileo’s time eventually adjusted to the astronomical facts, not just because they had to give a nod to reality but because the very idea that morality has something to do with a Great Chain of Being was daffy to begin with.

  We are now living, I think, through a similar transition. The Blank Slate is today’s Great Chain of Being: a doctrine that is widely embraced as a rationale for meaning and morality and that is under assault from the sciences of the day. As in the century following Galileo, our moral sensibilities will adjust to the biological facts, not only because facts are facts but because the moral credentials of the Blank Slate are just as spurious.

  This part of the book will show why a renewed conception of meaning and morality will survive the demise of the Blank Slate. I am not, to say the least, proposing a novel philosophy of life like the spiritual leader of some new cult. The arguments I will lay out have been around for centuries and have been advanced by some of hist
ory’s greatest thinkers. My goal is to put them down in one place and connect them to the apparent moral challenges from the sciences of human nature, to serve as a reminder of why the sciences will not lead to a Nietzschean total eclipse of all values.

  The anxiety about human nature can be boiled down to four fears:

  • If people are innately different, oppression and discrimination would be justified.

  • If people are innately immoral, hopes to improve the human condition would be futile.

  • If people are products of biology, free will would be a myth and we could no longer hold people responsible for their actions.

  • If people are products of biology, life would have no higher meaning and purpose.

  Each will get a chapter. I will first explain the basis of the fear: which claims about human nature are at stake, and why they are thought to have treacherous implications. I will then show that in each case the logic is faulty; the implications simply do not follow. But I will go farther than that. It’s not just that claims about human nature are less dangerous than many people think. It’s that the denial of human nature can be more dangerous than people think. This makes it imperative to examine claims about human nature objectively, without putting a moral thumb on either side of the scale, and to figure out how we can live with the claims should they turn out to be true.

  Chapter 8

  The Fear of Inequality

  THE GREATEST MORAL appeal of the doctrine of the Blank Slate comes from a simple mathematical fact: zero equals zero. This allows the Blank Slate to serve as a guarantor of political equality. Blank is blank, so if we are all blank slates, the reasoning goes, we must all be equal. But if the slate of a newborn is not blank, different babies could have different things inscribed on their slates. Individuals, sexes, classes, and races might differ innately in their talents, abilities, interests, and inclinations. And that, it is thought, could lead to three evils.

  The first is prejudice: if groups of people are biologically different, it could be rational to discriminate against the members of some of the groups. The second is Social Darwinism: if differences among groups in their station in life—their income, status, and crime rate, for example—come from their innate constitutions, the differences cannot be blamed on discrimination, and that makes it easy to blame the victim and tolerate inequality. The third is eugenics: if people differ biologically in ways that other people value or dislike, it would invite them to try to improve society by intervening biologically—by encouraging or discouraging people’s decisions to have children, by taking that decision out of their hands, or by killing them outright. The Nazis carried out the “final solution” because they thought Jews and other ethnic groups were biologically inferior. The fear of the terrible consequences that might arise from a discovery of innate differences has thus led many intellectuals to insist that such differences do not exist—or even that human nature does not exist, because if it did, innate differences would be possible.

  I hope that once this line of reasoning is laid out, it will immediately set off alarm bells. We should not concede that any foreseeable discovery about humans could have such horrible implications. The problem is not with the possibility that people might differ from one another, which is a factual question that could turn out one way or the other. The problem is with the line of reasoning that says that if people do turn out to be different, then discrimination, oppression, or genocide would be OK after all. Fundamental values (such as equality and human rights) should not be held hostage to some factual conjecture about blank slates that might be refuted tomorrow. In this chapter we will see how these values might be put on a more secure foundation.

  WHAT KINDS OF differences are there to worry about? The chapters on gender and children will review the current evidence on differences between sexes and individuals, together with their implications and non-implications. The goal of this part of the chapter is more general: to lay out the kinds of differences that research could turn up over the long term, based on our understanding of human evolution and genetics, and to lay out the moral issues they raise.

  This book is primarily about human nature—an endowment of cognitive and emotional faculties that is universal to healthy members of Homo sapiens. Samuel Johnson wrote, “We are all prompted by the same motives, all deceived by the same fallacies, all animated by hope, obstructed by danger, entangled by desire, and seduced by pleasure.”1 The abundant evidence that we share a human nature does not mean that the differences among individuals, races, or sexes are also in our nature. Confucius could have been right when he wrote, “Men’s natures are alike; it is their habits that carry them far apart.”2

  Modern biology tells us that the forces that make people alike are not the same as the forces that make people different.3 (Indeed, they tend to be studied by different scientists: the similarities by evolutionary psychologists, the differences by behavioral geneticists.) Natural selection works to homogenize a species into a standard overall design by concentrating the effective genes—the ones that build well-functioning organs—and winnowing out the ineffective ones. When it comes to an explanation of what makes us tick, we are thus birds of a feather. Just as we all have the same physical organs (two eyes, a liver, a four-chambered heart), we have the same mental organs. This is most obvious in the case of language, where every neurologically intact child is equipped to acquire any human language, but it is true of other parts of the mind as well. Discarding the Blank Slate has thrown far more light on the psychological unity of humankind than on any differences.4

  We are all pretty much alike, but we are not, of course, clones. Except in the case of identical twins, each person is genetically unique. That is because random mutations infiltrate the genome and take time to be eliminated, and they are shuffled together in new combinations when individuals sexually reproduce. Natural selection tends to preserve some degree of genetic heterogeneity at the microscopic level in the form of small, random variations among proteins. That variation twiddles the combinations of an organism’s molecular locks and keeps its descendants one step ahead of the microscopic germs that are constantly evolving to crack those locks.

  All species harbor genetic variability, but Homo sapiens is among the less variable ones. Geneticists call us a “small” species, which sounds like a bad joke given that we have infested the planet like roaches. What they mean is that the amount of genetic variation found among humans is what a biologist would expect in a species with a small number of members.5 There are more genetic differences among chimpanzees, for instance, than there are among humans, even though we dwarf them in number. The reason is that our ancestors passed through a population bottleneck fairly recently in our evolutionary history (less than a hundred thousand years ago) and dwindled to a small number of individuals with a correspondingly small amount of genetic variation. The species survived and rebounded, and then underwent a population explosion after the invention of agriculture about ten thousand years ago. That explosion bred many copies of the genes that were around when we were sparse in number; there has not been much time to accumulate many new versions of the genes.

  At various points after the bottleneck, differences between races emerged. But the differences in skin and hair that are so obvious when we look at people of other races are really a trick played on our intuitions. Racial differences are largely adaptations to climate. Skin pigment was a sunscreen for the tropics, eyelid folds were goggles for the tundra. The parts of the body that face the elements are also the parts that face the eyes of other people, which fools them into thinking that racial differences run deeper than they really do.6 Working in opposition to the adaptation to local climates, which makes groups different on the skin, is an evolutionary force that makes neighboring groups similar inside. Rare genes can offer immunity to endemic diseases, so they get sucked into one group from a neighboring group like ink on a blotter, even if members of one group mate with members of the other infrequently.7 That is why Jews,
for example, tend to be genetically similar to their non-Jewish neighbors all over the world, even though until recently they tended to marry other Jews. As little as one conversion, affair, or rape involving a gentile in every generation can be enough to blur genetic boundaries over time.8

  Taking all these processes into account, we get the following picture. People are qualitatively the same but may differ quantitatively. The quantitative differences are small in biological terms, and they are found to a far greater extent among the individual members of an ethnic group or race than between ethnic groups or races. These are reassuring findings. Any racist ideology that holds that the members of an ethnic group are all alike, or that one ethnic group differs fundamentally from another, is based on false assumptions about our biology.

  But biology does not let us off the hook entirely. Individuals are not genetically identical, and it is unlikely that the differences affect every part of the body except the brain. And though genetic differences between races and ethnic groups are much smaller than those among individuals, they are not nonexistent (as we see in their ability to give rise to physical differences and to different susceptibilities to genetic diseases such as Tay-Sachs and sickle cell anemia). Nowadays it is popular to say that races do not exist but are purely social constructions. Though that is certainly true of bureaucratic pigeonholes such as “colored,” “Hispanic” “Asian/Pacific Islander,” and the one-drop rule for being “black,” it is an overstatement when it comes to human differences in general. The biological anthropologist Vincent Sarich points out that a race is just a very large and partly inbred family. Some racial distinctions thus may have a degree of biological reality, even though they are not exact boundaries between fixed categories. Humans, having recently evolved from a single founder population, are all related, but Europeans, having mostly bred with other Europeans for millennia, are on average more closely related to other Europeans than they are to Africans or Asians, and vice versa. Because oceans, deserts, and mountain ranges have prevented people from choosing mates at random in the past, the large inbred families we call races are still discernible, each with a somewhat different distribution of gene frequencies. In theory, some of the varying genes could affect personality or intelligence (though any such differences would at most apply to averages, with vast overlap between the group members). This is not to say that such genetic differences are expected or that we have evidence for them, only that they are biologically possible.