We, homo sapiens, are about to learn how to alter human nature at about the same time that we finally learn for sure what that human nature is. Our ignorance about the underlying truth of human nature has not been for want of trying. But philosophers have produced answers as various as Aristotle's and Rousseau's. Since the late 1900s, behavioural and social scientists have also tried to understand human nature. But while they have illuminated many useful bits and pieces, they have failed as system-builders. What is left of Freud out of the beliefs that were so intellectually pervasive in mid-century? Psychotherapy remains, in profuse variety, but only remnants of Freudianism. What is left of BF Skinner? Behaviourism is still a productive branch of psychology, but the Skinner vision of human nature is dead. As for Marx, does anything at all survive? For more than a century, Marxism throughout continental Europe was the leading intellectual framework for thinking about how political institutions could realise the nature of man. That edifice has utterly collapsed.
How can we have expended so much of our collective genius on understanding human nature and still know so little for certain? Because, up until now, we have been able to observe only behaviour. People can hold very different views of human nature-man is by nature altruistic or by nature selfish; by nature amoral or by nature endowed with a moral sense-because we observe in the human animal, in abundance, every sort of behaviour. Or, to put it statistically, human nature does not consist of universal human characteristics, but of distributions. Is mankind altruistic or selfish? From everyday experience, we know that some people behave selfishly and some altruistically. When we say that human beings are by nature altruistic or selfish, we are actually saying that a distribution of the human population on the characteristic of "underlying biological propensity to altruism" will have a certain shape and median. The implications of a distribution in which, for example, the average value is "fairly selfish" has very different implications from a bell curve in which the average value is "fairly altruistic." The implications of a curve that is narrow and steep (meaning that almost all human beings are very close to the median value) are very different from those of a shape that is wide and short (meaning that human nature for this characteristic is all over the map).
The problem is that, while scientists can measure the observed shape of these behaviours, they have been stymied by the nature/nurture problem. This is not to say that we know nothing. Just as geologists know a lot about the probability of finding oil, based on rock formations on the surface, psychologists have learned to infer a lot about the heritability of observed traits. But in both cases, the observer is dealing with outcroppings and probabilities, while the exact, inarguable truth lies hidden.
This situation is about to change. No one can tell how rapidly and how completely the story will unfold. A few brave souls-brave, indeed, to buck the consistent lesson of the last 500 years of science-still argue that the mysteries of the human mind will forever be mysteries. But EO Wilson's reading of the situation in his 1998 book, Consilience, seems much more plausible. The neuroscientists, understanding increasingly how the brain works, and the molecular biologists, understanding increasingly which genes do what, are about to link up with the social sciences, according to Wilson, in a "webwork of causal explanation" which brings human behaviour within the realm of rigorous investigation previously reserved for physical phenomena. And not just individual behaviour. "The explanatory network now touches on the edge of culture itself," in Wilson's words-or, to put it another way, we are on the edge of understanding how human nature in individuals produces social and political institutions.
What we know now is fragmentary. But the speed with which that knowledge is expanding is so fast that we can reasonably expect to know a great deal about many aspects of human nature and their social implications within just a few decades. By the end of the 21st century we will be approaching biological truths about these topics.
It will be a winding road, with many false pronouncements which will be revised a year later, as new data come to light. Even those new findings that are solidly based will seldom be exciting individually. We will not find an aggression gene nor a marriage gene nor an IQ gene. Instead, we will learn about complex combinations of genes and their alleles which affect a behaviour, and about how they interact with the unimaginably complicated neural and hormonal processes which affect behaviour. We will learn about the interaction between biology and environment.
The practical importance of these impending discoveries lies in this: the great conflicts of the last two centuries have in large part been the story of differing views of human nature translated into political codes. Communism's use of Marxism was the paradigmatic example, aggressively asserting that human nature is soft plastic which can be moulded into any configuration by society's political and economic institutions. But the debates over social policy within the democratic west have also been underlain by conflicting understandings of human nature. Are mothers peculiarly suited to raising small children, or can fathers do it just as well? Should women be in combat? The positions we adopt are based on assumptions about innate differences between men and women. The welfare state makes sense-or doesn't-depending on underlying beliefs about how human beings achieve satisfaction in life. Should we try to deal with crime by attacking root causes? Depending on your definition of "root causes," attacking them could mean an anti-poverty programme or more prisons-and your definition can ultimately be traced back to your beliefs about human nature.
It will be a cumulative process. But as time goes by, our increasingly certain knowledge of human nature is going to shrink the wiggle-room for certain political positions. Let us think of the process as a scientific version of the Alger Hiss case (a leading American liberal accused of being a Soviet spy). As of 2000, we have, analogously, already discovered the Pumpkin Papers (which suggested that Hiss was not as innocent as most liberals assumed). The scientific literature already in hand, not to mention common sense, gives us a pretty good idea of where this story is leading, just as dispassionate observers in 1948 had a pretty good idea that Hiss was guilty. Hiss's advocates defended his innocence for decades after the Papers were found, but those advocates dwindled as new evidence periodically came to light. Finally, the Venona intercepts were revealed, and the debate effectively ended. So it will be with the uncovering of human nature.
The choice of analogy betrays my own expectations of the unfolding story. What we already know leads me to believe that the story of human nature, as revealed by genetics and neuroscience, will be Aristotelian in its philosophical shape and conservative in its political one. We will learn some things for certain, for example that women innately make better nurturers of small children than men do and that men innately make better soldiers than women do. Regarding these and many other human characteristics impinging on marriage, the upbringing of children, and the enforcement of social order, I predict that the adages of the right will usually prove to be closer to the mark than the adages of the left, and that many of the causes of the left will be revealed as incompatible with the way human beings are wired.
To put it in terms of left versus right, however, understates the magnitude of what is likely to happen. Of all the casualties of our growing knowledge of human nature, the most politically far-reaching will be the 20th century's curious attachment to literal human equality. The response to The Bell Curve illustrates what uncharted territory we are sailing into. As authors of the book, Richard Herrnstein and I thought that The Bell Curve contained powerful ammunition for the left. If IQ is important in determining life's outcomes, and IQ is not acquired by merit, then one legitimate line of argument is that the government should intervene to make up for the unfairness of nature and capitalism. We did not realise how important the egalitarian premise is to the world-view of the left. It is not enough that governments guarantee equal rights for all; it is not even enough that governments intervene to equalise outcomes. It must also be that inequalities in individuals are the result of the social, economic and political system, rather than of inherent differences in ability. I am still not sure why this premise is so important-the case for redistributionist policies does not depend on it-but it is.
In their own way, politicians of the right are equally in thrall to the egalitarian premise. For example, no major Republican politician is willing to say in public that some of the social problems which we most deplore are rooted in some degree in personal deficiencies. Try to imagine a GOP presidential candidate saying in front of the cameras: "One reason that we still have poverty in the US is that a lot of poor people are born lazy." You cannot imagine it, because that kind of thing cannot be said. And yet this unimaginable statement merely implies that when we know the complete genetic story, it will become evident that the population below the poverty line in the US has a configuration of the relevant genetic makeup significantly different from the configuration of the population above the poverty line. This is not unimaginable. It is almost certainly true. It is also certainly true that statistically significant distributions of biological makeup separate almost all other groups which show substantially different patterns of behaviour.
The group differences that people are obsessed with have to do with race and sex, but I want to reach past that reflexive response to make a broader point. Statistically significant genetic differences, beyond the self-evident ones, probably separate men from women, and people who call themselves "white" from people who call themselves "black" or "Asian." But they also probably distinguish the English from the French, employed Swedes from unemployed Swedes, observant Christians from lapsed ones and people who collect stamps from people who backpack.
None of this should be earthshaking. Often we will be talking of group differences so subtle that they can be teased out only by the most sophisticated methods. Often these differences will have nothing to do with "better" or "worse," but simply vive la diff?rence. Even when the differences are substantial, the variation between two groups will almost always be dwarfed by the variation within groups-meaning that the overlap between two groups will be great. In a free society where people are treated as individuals, "So what?" is to me the appropriate response to genetic group differences. The only political implication of group differences is that we must work hard to ensure that our society is in fact free, and that people are in fact treated as individuals. And yet I can tell you, from personal experience, that "So what?" is not a response shared by many. Today, to suggest that genetically-based group differences are even probable provokes a reaction that resembles hysteria.
Now imagine a world a few decades hence, in which it has been demonstrated that biologically-based differences do separate individuals and groups, and that some of these differences involve characteristics which are important to success in life. What will happen when a position which is taboo in public discourse is proved to be scientifically accurate?
Nothing will happen, it might be argued. Even now, hardly anyone really believes in his heart of hearts that the strictly egalitarian line is true, so what difference will scientific proof make? But history suggests otherwise. Thomas Kuhn taught us in The Structure of Scientific Revolutions that, first, the old scientific paradigm begins to show cracks, then those cracks spread, and then, with remarkable speed, Kuhn's famous "paradigm shift" occurs. In just a few years there are no more Ptolemaic astronomers, only Copernican ones; no more Aristotelian physicists, only Newtonian ones. Today, we are at the stage of the spreading cracks, even if the egalitarian premise seems more politically impregnable than ever. But when the scientific debate eventually ends, it will not be merely a matter of scientists on the wrong side saying, "Oh, well," while the rest of our intellectual perspective continues unchanged; with the displacement of the old paradigm comes a new way of looking, not just at isolated bits of scientific truth, but at the way the world works. Think of the Newtonian revolution and the Enlightenment. Close to our own time, the Darwinian and Einstein revolutions were central to the development of the non-scientific intellectual world of the 20th century. So it will be with the consequences of the neurogenetic revolution which is about to unfold. It will have transforming effects which spill over into our conceptions of politics, religion, and social relationships.
in my view, one of the most likely spill-overs is that eugenics will become a cause of the left. Eugenics is in disrepute because of Nazism, but this has made us forget that, before Nazism, it referred to a movement centred in Britain that was respectable and especially popular among intellectuals. Simply put, the eugenicists made an assertion and drew from it a policy implication. Their assertion was that social problems would be greatly reduced if the lower classes had fewer children and the better educated classes had more. The policy implication was that government policies should encourage the result.
As the biological basis for personal qualities statistically associated with social problems-low IQ, impulsiveness, short time-horizons, sociopathy, indolence-is understood, the old arguments about causality (such as "it's poverty which creates the low IQ, not the other way round") will be resolved. There will still be a large role for environmental causes and solutions to social problems, but understanding the portion that is biological will permit analysts of the future to make fairly precise forecasts about the extent to which changes in fertility patterns may be expected to affect crime and poverty. The difference will be that the old eugenicists had to rely on a rough statement ("the lower classes"), whereas future eugenicists will be able to be more precise ("people with the following genetic profiles").
Now turn to the eugenicists' political conclusion: that government should act to shape fertility patterns. It is not something that today's left likes to recall, but eugenicism was mainly a movement of the British Fabian and socialist left, not of Tories or Liberals. The political affinity was expressed by Sidney Webb: "No consistent eugenicist can be a 'laissez-faire' individualist," he wrote, "unless he throws up the game in despair. He must interfere, interfere, interfere!" Sidney and Beatrice were joined in their enthusiasm for eugenics by the likes of George Bernard Shaw, Emma Goldman and HG Wells.
As genetic engineering matures, a new, more insidious brand of eugenics will become possible-one which does not require the lower classes to stop having children, only to start having better children. This will be eugenics tailor-made for a left constituted of people who are more squeamish than their forebears about being repressive, but who are just as ready to interfere, interfere, interfere in a good cause. Will the right stand firm against this ultimate intrusion of government? I pray so. But don't bet on it.
I have no idea how the new eugenicism will play out-only a general expectation that eugenics, anathema today, will be a spin-off of the neurogenetic revolution tomorrow. My main point is that many such effects will be triggered, that most of them are now unforeseeable, and that this will turn the intellectual and political landscape topsy-turvy.
What of the broader manipulation of human nature? Putting aside government intervention and confining ourselves to the voluntary choices of individuals, should we expect that Homo sapiens will take it into its collective head to redesign itself? I confess to a certain optimism. I suppose that sex selection will be common, and that some parents will, if they can, opt to make their babies more compassionate, or more competitive, or "more" of some other personality trait that they favour. Some parents may want to grow seven-foot-tall basketball players. But one of the main reasons why couples have babies is to produce their baby, the product of their combined genes. Motivations don't get much more basic than that, and I think it unlikely that the typical parent will want to distort the process too much. The popular voluntary uses of gene manipulation are likely to be ones which avoid birth defects and ones that lead to improved overall physical and mental abilities. I find it hard to get upset about that prospect.
We may hypothesise a variety of darker sides to the ability to manipulate human tendencies. There are the unforeseeable effects of homogenisation. A world in which all children are above average might be duller than we suppose. Nor am I confident in our ability to tweak the human sense of the rhythm of life to correspond with the extensions of life span which may occur. More broadly, our ability to affect the physical aspect of the human animal may run ahead of our ability to accommodate those changes to the ways in which the human psyche achieves happiness.
But these specific worries are the ruminations of a 20th-century man, destined to look as myopic a century from now as the predictions of 19th-century men about the 20th century. I am confident of just one thing. Many of you reading these words will live to see one of Kuhn's paradigm shifts-one as broad and deep, as demoralising and inspiring, as destructive and creative, as any which have taken place before.
