Gavin Evans’s criticisms of attempts to demonstrate a robust association between surrogate measures of ill-defined concepts (“race” and “intelligence”) are to the point (The unwelcome return of ‘race science’, The long read, 2 March). However, the dogma underpinning these attempts – genetic determinism – is left unchallenged. This determinism asserts that sequences of nucleotides comprising our chromosomes specify the characteristics – in their entirety – of the individual. It is a sad fact that the confusing phrase the “selfish gene” originated from a former professor for public understanding of science at the University of Oxford.
Today, this reductionist approach to biology – and therefore to human biology – has been displaced by a more profound interpretation of the facts. “Systems biology” (see Denis Noble’s proposals on “biological relativity” in his new book Dance to the Tune of Life) sees an organism as comprising levels of relatively autonomous organisation each interacting with their total environment. Critical features of each of these levels cannot be predicted from the sequences of nucleotides. Genetic determinism is just plain wrong.
When it comes to the sensitivity of humans to their total environment, to their powers of reasoning about that environment, to their “intelligence”, the sources of variation in that sensitivity should be sought at the appropriate level of organisation of the individual. The best evidence points to the environmental system in which humans exist: cultural patrimony (including the prejudices), education and economic status. As Evans implies, nucleotides don’t seem to come into it.
Division of population health, University of Manchester
• Scientific racism never dies but merely lies dormant, waiting the political moment to rise from its coffin. Back in the 1960s, the US educational psychologist Arthur Jensen claimed that the difference in IQ scores between US white people and black people was genetically determined – swiftly endorsed in the UK by Hans Eysenck. A group of younger psychologists and biologists took on the challenge of refuting their claims. We sought support from our elders, notably the distinguished evolutionist John Maynard Smith. You could sense the weariness in John’s response; they had done this all before, in the 1930s. Did it really need to be done again? It did, and he and we did it. And if it needs doing once again, so we must.
Emeritus professor of neuroscience, The Open University
• Everyone can trace their ancestry and genes back to three relatively small migrations from east Africa: an early one of Homo erectus some 400,000 years ago that led to the Neanderthals and Denisovans, and two later ones by Homo sapiens. One migration 70,000 years ago led to the indigenous Australians; while the descendants of a migration 60,000 years ago slowly colonised the world. Genetic analysis shows that this latter group originally included little more than a thousand people. Colonisation happened as small founder groups successively left larger, stable groups to settle new areas, interbreeding as they went with Denisovans in Asia and Neanderthals in Europe. We know this because the further a modern group is from Africa, the smaller is the diversity of its gene pool, while all the genes present in non-African populations are found in African ones. However, given the great degree of migration and interbreeding since those early times, very few people reflect a pure line of inheritance.
There is also a key point about genes that is important here. Originally, a gene was recognised by its effect on a characteristic that varied across a population (skin colour, size, cranial capacity etc), a view that harks back to Mendel in 1869. Since the 1960s, however, it has become clear that a gene is actually a piece of DNA that does something at the molecular level (eg coding for a protein or regulating its expression). Producing a characteristic is a much higher-level and more complicated business: the networks that regulate growth, for example, typically include about sixty proteins.
The idea that there is a gene for intelligence, facial feature or any other characteristic is just plain wrong, as are the ideas put forward by race scientists.
Emeritus professor, Oxford
• I would have hoped “race science” had been permanently knocked on the head by Stephen Jay Gould’s The Mismeasure of Man. Gould’s critique is more radical than Evans’s, in that he debunks the claim that intelligence is a single numerical value measured by IQ tests, and exposes psychometry itself as pretend science. He points out that IQ tests were originally designed as aptitude tests with no claim that they measured anything more fundamental.
• Isn’t race science an attempt to prove some people are inferior or expendable due to their careless choice of parents and/or birthplace? It doesn’t seem scientific or even sane to me.
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