It is a curious paradox that those who inveigh most vehemently against race as a concept also campaign most vigorously for racial quotas by means of affirmative action. It is only a seeming paradox, however, because it is possible to acknowledge the existence of discrimination on the basis of mere physical difference without ascribing to that difference any greater taxonomic significance than its capacity to evoke the discrimination itself. Nevertheless, the very vehemence of the denial suggests some kind of whistling in the dark. And there is one further oddity to be remarked: While history is full of instances of discrimination against others, now is surely the first time in history that a group has proposed to discriminate against itself (no positive affirmation being possible without its negative corollary). Expiation for the sins of one’s ancestors, rather than truth or justice, is what is sought—usually bought at someone else’s expense, of course.

Nicholas Wade, the science editor of The New York Times, has written a book that will no doubt win him many brickbats. In it, he argues that race is a perfectly valid scientific concept and one that is supported by the latest genetic science. It is no criticism of race as a biological concept, he says, that races have no clear boundaries and that gradations between them obviously exist, for if clear boundaries existed and the races could not interbreed, they would be different species, not races. A race is a population of a single species with a cluster of genetic variants, the presence of none of which is either a necessary or a sufficient condition of being a member of that race, but which nevertheless in aggregate gives that population distinguishing characteristics.

According to the author, there are five basic races of man, as revealed by the clustering of genetic variants: African, Caucasian (including Semitic and South Asian), East Asian, Amerindian, and Australian. There are also sub-variants within the races: for example Ashkenazi Jews, who are Caucasians but have managed for cultural reasons to maintain a genetic profile of their own. Furthermore, he says that race is of some explanatory value in world history, for the races evolved under different environmental pressures, and it is reasonable to suppose that these pressures gave rise to different psychological, as well as physical, characteristics. For example, the hypotheses that Chinese geography (unlike European) favored the emergence of a centralized state; that this necessitated the development of a powerful bureaucracy; that the kind of person who flourishes economically in such a bureaucracy, more of whose children survive to pass on their genes, is intelligent but conformist; and that therefore the Chinese are genetically more intelligent but by nature more conformist than Europeans. In point of scientific inventiveness, the effect of their conformism more than cancels out that of their superior IQ, which is why East Asian societies are still not scientific powerhouses.

Fourteen percent of the human genome, says the author, has been subject to “evolution that has been recent, copious, and regional”—not enough to divide humanity into species, but enough to make physical and mental differences between populations.

In view of the potentially explosive nature of these claims, the author is at pains to point out that no policy prescription follows from them, certainly not exploitation or genocide of one race by another. Political equality is an ethical or metaphysical concept, not one that relies for its validity on an empirical fact other than that mankind is a single species. That the concept of race has been used to justify the most hideous of crimes should no more inhibit us from examining it dispassionately as a biological and historical reality than the fact that economic egalitarianism has been used to justify crimes just as hideous should inhibit us from examining the effects of modern income distribution.

Even though the author does not crudely claim that race determines civilization, but rather that there is a constant dialectical interplay between physical environment, natural selection of advantageous physical and psychological characteristics in that environment, and the type of society to which those advantageous characteristics will give rise (an interplay that is as unending as evolution itself), I found his argument for the important historical effect of biological race on history unconvincing.

Quite early in the book, the author produces a map to illustrate the supposed interplay between genetics and culture. It is a map of Europe showing the distribution of the population with and without lactose intolerance, that is to say of the population that produces and does not produce the enzyme, lactase, that breaks down lactose, the sugar in milk. The difference between the lactose tolerant and intolerant is genetic; so, the author claims, those areas where the great majority of the population are not lactose intolerant are areas with strong dairy farming. The direction of the causal relation between the lactose tolerance and the dairy farming is not absolutely clear.

There is something very odd about this map. The further one moves in Europe from the land around the Baltic, the more prevalent lactose intolerance becomes, until in France it is very high. But France is notoriously the country that produces more varieties of cheese than the rest of the world put together, and whose production and consumption of yogurt is probably the highest in the world. (The latter is a comparatively recent development—until the 1950s yogurt was produced on a domestic scale and even then its production was not very widespread). Even allowing for the relative innocuousnesss to those with lactose intolerance of yogurt and some cheeses compared with milk, the map does not fit; and it should be remembered that there are factors other than genetic in the development of lactose intolerance. Either the map, or the point it is trying to make, is wrong.

There are other errors. The author tries to make out that the decline in the homicide rate in the western world is the result of genetic changes that gave survival advantage in new social circumstances to those who were less inclined to aggression and personal violence. These social circumstances not having yet developed in Africa, the homicide rate in the latter continent remains much higher than in Europe or the United States, the implication being that Africans are genetically more violent than the populations of Europe and the USA.

The author paints with far too broad a brush. Are there really no variations in the regions and countries of Africa, both in time and place? Is there really such continental uniformity? This was certainly not my experience of Africa, and I once travelled across it by public transport, such as it was.

Moreover, the statistics that the author uses are suspect. He says of the United States that its homicide rate is less than 2 per 100,000. The last time I looked the rate was 4.7 per 100,000—itself a very sharp decline of recent years. But a paper not long ago suggested that if the same resuscitation and surgical techniques were used as were used in 1960, the homicide rate in the United States would be five times higher than it is today, that is to say 23.5 per 100,000. The new techniques in surgery and resuscitation are unlikely to have reached much of Africa, where (the author says) the homicide rate is 10 per 100,000. In other words, either the statistics in Africa are unreliable—which in my opinion is very likely—or the statistics prove precisely the opposite of what the author wants to prove. Either way, his point is vitiated.

When our author says that western society has become much less violent, thanks (possibly) to mutations in the genes that control brain chemistry, the question naturally arises “Compared with when?” Why should we compare our current levels of violence with those of the year 1200 rather than with those of 1950, which is within the memory of many still alive? To take but one example: The number of crimes of violence in New Zealand per head of population rose by a factor of 175 between 1950 and 1999. Even allowing for possible differences in the definition and measurement of violent crime, this is a difference so startling that it is completely implausible to attribute it mainly or even partially to genetics. And, to do him justice, the author wouldn’t. But this means that non-genetic factors can easily make genetic ones seem minor. In Britain, the rate of addiction to heroin in the population rose 25,000 percent between the mid-1950s and 2010. Genetics had nothing to do with this. The difference between North Korea and South—as great as that between Ukraine and Africa, say—has nothing to do with genetics.

There are many other problems with the author’s thesis. He takes seriously the frequently repeated statement that hundreds of millions of Africans live on less than $1 per day. Only a moment’s reflection is, or should be, necessary to establish the meaninglessness of such a statement. The notion that the average monetary value of the economic product per head of population was no different between the western world and that of, say, Africa until the Industrial Revolution, and that this fact, if it is a fact (which I very much doubt), is of any importance, is extremely doubtful. No one who visits Venice, say, and then the ruins of Great Zimbabwe—in its heyday, the acme of African cultural and material achievement for hundreds of miles around—could possibly doubt that there was an immense gulf in the intellectual achievement and sophistication of the two civilizations, even if the peasants of both lived at the same level. But the difference between Great Zimbabwe and the Masai is, or was, just as great as that between Venice and Great Zimbabwe.

By far the most interesting and convincing chapter in the book is that concerning the intellectual preeminence in the modern world of the Ashkenazi Jews. If the author’s thesis applies anywhere, it is here. But he entirely omits to mention a conditio sine qua non of the Ashkenazi rise to preeminence, namely the European Enlightenment. And surely the name of Napoleon, not entirely worthy of respect in all other contexts, is here worth mentioning with honor. Without the Enlightenment, Ashkenazi intelligence, even if wholly genetic, could not have made so important a contribution to western civilization.

Mr. Wade is a courageous man, as is anyone who dares raise his head above the intellectual parapet; he has put his argument with force, conviction, intelligence, and clarity. He has drawn attention to possibilities that we ignore, probably as much because we prefer to ignore them as because we do not think them true on the evidence. All the same, I was not convinced: Perhaps, though not Chinese, I have the genes for conformity.