The men’s 100m at the World Athletics Championships in Japan this month will be won by a black athlete. This is not so much a prediction as a statement of fact. Every winner of the 100m at the championships since the inaugural event in 1983 has been black, as has every finalist from the last eight championships. No white athlete has reached the final of the Olympic Games for more than a quarter of a century. Of the 53 athletes to have ducked under ten seconds, all are black.

There is a natural conclusion to be drawn from all this: blacks have an inbuilt superiority over whites when it comes to sprinting. Many scientists and writers have made this claim, to the fury of equal rights campaigners who fear that any acknowledgement of natural differences between the races might usher in a new wave of racism. Similar claims are familiar: blacks are inferior swimmers, yellows are better ping-pong players, and so on. But do such differences exist and what would it mean if they did? The answer cuts to the heart of our understanding of race and human diversity at the beginning of the 21st century.

The prototypical argument for black athletic superiority can be found in Taboo: Why Blacks Athletes Dominate Sports and Why We Are Afraid to Talk about it by Jon Entine. Entine’s central assertion is that it is not blacks as a whole that are good at sprinting but rather a subset who can trace their origins to western African coastal states. Indeed, he makes the point that “no white, Asian or East African runner has broken 10 seconds in the 100m” (my italics).

East Africans, it turns out, have a rather different skill set: distance running. As has been well documented, Kenyans from well-defined areas in the Rift Valley are strikingly successful at running 3,000m and above. Up until 1993 the Kalenjin tribe won 317 medals and the neighbouring Gussi people won 78. These figures amounted respectively to 63 per cent and 15 per cent of the 506 medals won by Kenyan athletes in major competitions.

Let us assume that these results have genetic causes. Is Entine entitled to conclude that blacks are naturally better athletes? Well, no. All he is entitled to say is that East Africans are naturally better at distance running and West Africans are naturally better at sprinting and that whites are probably somewhere in the middle at both disciplines. So why make the further claim that “blacks” are naturally better at sprinting and distance running? The fallacy may not seem obvious because we are so used to thinking that “black” and “white” refer to biologically significant groupings. So let us imagine a similar argument using the Central African Bambuti, a tribe commonly referred to as Pygmies. With an average height of 4ft we can safely assert that the Bambuti have a natural superiority when it comes to walking under low ceilings. Would it be legitimate to extrapolate from this that blacks in general have a natural advantage at walking under low ceilings? The problem for the “racial scientist” is his yearning to generalise.

Finding genetic variation between populations (such as the Rift Valley) is common. Small populations have distinct genetic traits because nature has selected physiques that suit their natural environments: the short-limbed Inuits, for example, are physically different from the Australian Aborigines. Such genetic differences between populations exist across the planet. But why lump together all the diverse populations that happen to share similar skin pigmentation?

Some scientists have resorted to smuggling in racial categories under an epidemiological guise. For example, blacks are said to be more predisposed to sickle cell anaemia. The truth, again, is more complex. Sickle cell anemia disproportionately affects the descendants of populations who lived in malarial zones, which means a higher risk for those whose ancestors came from certain parts of sub-Saharan Africa. But it also implies a higher risk for those who hail from areas in the southern Mediterranean. Genetic diseases are not racial per se. Many other so-called black diseases are in fact diseases of poverty with well-established environmental causes.

The reason why racial scientists are able to get away with crude and statistically dubious generalisations is because they chime with our natural inclination to regard “black” as a genetic type distinct from “white” or “yellow”. Indeed, this inclination is so powerful that it requires an effort of will to free oneself from its clutches.

But it is worth the effort. The fact is that there are probably no human races at all as the term is used in the biological sciences. The so-called races blend together so smoothly that it is unlikely that we will ever find a genetically rigorous demarcation that will allow us to categorise Homo sapiens in the way that we can some other species.

And even if better familiarity with the human genome does enable us to make such a classification, we can be sure that it will never correspond with “black”, “white” and “yellow” as we colloquially use the terms. How could it when the terms themselves are without clear boundaries — as anyone who has traced the continuum in skin pigmentation from Iceland to sub-Saharan Africa will tell you?

None of this will be of any surprise to those familiar with genetics, which tells us that most genetic variation (around 85 per cent) is to be found within groups rather than between them. In fact, almost all human genetic variation can be found within single African tribes, because of Africa’s place as the cradle of humanity. To the extent that there is genetic variation between groups, the majority is geographical rather than “racial”. Indeed, surface appearance (such as skin colour) can often be highly misleading when it comes to identifying the genetic distance between populations.

The conclusion is unavoidable: those who invoke race as an explanation of real and perceived differences between humans have an agenda that is other than scientific.

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