The Orwellian disinformation about innate group differences is not wholly the media's fault. Many academics who are familiar with the state of knowledge are afraid to go on the record. Talking publicly can dry up research funding for senior professors and can cost assistant professors their jobs. But while the public's misconception is understandable, it is also getting in the way of clear thinking about American social policy.
Good social policy can be based on premises that have nothing to do with scientific truth. The premise that is supposed to undergird all of our social policy, the founders' assertion of an unalienable right to liberty, is not a falsifiable hypothesis. But specific policies based on premises that conflict with scientific truths about human beings tend not to work. Often they do harm.
One such premise is that the distribution of innate abilities and propensities is the same across different groups. The statistical tests for uncovering job discrimination assume that men are not innately different from women, blacks from whites, older people from younger people, homosexuals from heterosexuals, Latinos from Anglos, in ways that can legitimately affect employment decisions. Title IX of the Educational Amendments of 1972 assumes that women are no different from men in their attraction to sports. Affirmative action in all its forms assumes there are no innate differences between any of the groups it seeks to help and everyone else. The assumption of no innate differences among groups suffuses American social policy. That assumption is wrong.
When the outcomes that these policies are supposed to produce fail to occur, with one group falling short, the fault for the discrepancy has been assigned to society. It continues to be assumed that better programs, better regulations or the right court decisions can make the differences go away. That assumption is also wrong.
Hence this essay. Most of the following discussion describes reasons for believing that some group differences are intractable. I shift from "innate" to "intractable" to acknowledge how complex is the interaction of genes, their expression in behavior, and the environment. "Intractable" means that, whatever the precise partitioning of causation may be (we seldom know), policy interventions can only tweak the difference at the margins.
I will focus on two sorts of differences: between men and women and between blacks and whites. Here are three crucial points to keep in mind as we go along:
1. The differences I discuss involve means and distributions. In all cases, the variation within groups is greater than the variation between groups. On psychological and cognitive dimensions, some members of both sexes and all races fall everywhere along the range. One implication of this is that genius does not come in one color or sex, and neither does any other human ability. Another is that a few minutes of conversation with individuals you meet will tell you much more about them than their group membership does.
2. Covering both sex differences and race differences in a single nontechnical article, I have had to leave out much. I urge that readers with questions consult the fully annotated version of this essay, which includes extensive supplementary material; it is available here at Commentary's Web site.
3. The concepts of "inferiority" and "superiority" are inappropriate to group comparisons. On most specific human attributes, it is possible to specify a continuum running from "low" to "high," but the results cannot be combined into a score running from "bad" to "good." What is the best score on a continuum measuring aggressiveness? What is the relative importance of verbal skills versus, say, compassion? Of spatial skills versus industriousness? The aggregate excellences and shortcomings of human groups do not lend themselves to simple comparisons. That is why the members of just about every group can so easily conclude that they are God's chosen people. All of us use the weighting system that favors our group's strengths.....
Since we live in an age when students are likely to hear more about Marie Curie than about Albert Einstein, it is worth beginning with a statement of historical fact: Women have played a proportionally tiny part in the history of the arts and sciences. Others have found similar proportions. Even in the 20th century, women got only 2% of the Nobel Prizes in the sciences--a proportion constant for both halves of the century--and 10% of the prizes in literature. The Fields Medal, the most prestigious award in mathematics, has been given to 44 people since it originated in 1936. All have been men.
The historical reality of male dominance of the greatest achievements in science and the arts is not open to argument. The question is whether the social and legal exclusion of women is a sufficient explanation for this situation, or whether sex-specific characteristics are also at work.
Mathematics offers an entry point for thinking about the answer. Through high school, girls earn better grades in math than boys, but boys usually do better on standardized tests. The difference in means is modest, but the male advantage increases as the focus shifts from means to extremes. In a large sample of mathematically gifted youths, for example, seven times as many males as females scored in the top percentile of the SAT mathematics test. We do not have good test data on the male-female ratio at the top one-hundredth or top one-thousandth of a percentile, where first-rate mathematicians are most likely to be found, but collateral evidence suggests that the male advantage there continues to increase, perhaps exponentially.
Evolutionary biologists have some theories that feed into an explanation for the disparity. In primitive societies, men did the hunting, which often took them far from home. Males with the ability to recognize landscapes from different orientations and thereby find their way back had a survival advantage. Men who could process trajectories in three dimensions--the trajectory, say, of a spear thrown at an edible mammal--also had a survival advantage. Women did the gathering. Those who could distinguish among complex arrays of vegetation, remembering which were the poisonous plants and which the nourishing ones, also had a survival advantage. Thus the logic for explaining why men should have developed elevated three-dimensional visuospatial skills and women an elevated ability to remember objects and their relative locations--differences that show up in specialized tests today.