28 October 2013
Dominic Cummings, outgoing special adviser to education secretary Michael Gove, set the cat among the pigeons with his views on genetics and education policy (as reported in BioNews 727). One of his points, that many people in education and beyond do not understand the concepts underlying the study of genetics and human differences and/or do not want to engage with the possible implications of this work, was amply proven by the response to his leaked thesis.
Distinguished Guardian columnist, Polly Toynbee, accused him of claiming that '70 percent of cognitive capacity is genetic, beside which the quality of teaching pales into insignificance'. Writing in The Telegraph, geneticist Steve Jones said: 'A closer look shows just how misleading it is to use heritability as a key to educational policy'.
The irony, of course, is that Cummings did not make the claim that Toynbee accused him of and does in fact understand the basic point Jones makes about heritability. In a radio discussion with Cummings' primary source, behaviour geneticist Robert Plomin, Jones had the good grace to admit that he had leapt into print without reading Cummings' own words. And significantly, during the discussion, Jones agreed to a large degree with Plomin that the past three decades and more of research have established that school test scores, like IQ scores, show a significant heritability (between 50 percent and 70 percent). So what do Cummings and Plomin actually argue, and what to make of it?
Cummings and Plomin are claiming a great deal, some of which is sound, some of which is not and some of which is very speculative. Let's start with the claim that 70 percent of the variation in IQ and IQ-type tests is down to genetics. That is a statement about variation in a given population at a given moment in time. IQ scores are re-normalised to keep the average at 100. The famous Flynn effect points to the fact that if we don't do this the mean goes up. Flynn and others have produced some fascinating work on this issue, about the relationship between knowledge and intelligence, and how learning new and different kinds of material could stimulate conceptual thinking and lead to a rise in the non-normalised mean. He breaks it down by historical period and class.
But we also need to ask whether we're comparing apples and oranges: that is, making a category mistake. Intelligence, after all, isn't a biological thing, or not entirely so, whereas genes are physical things. Differences in a physical thing can have consequences for something that is more than physical, so genetic variation can and does affect variation in cognitive ability. But this requires theorising and it's certainly a nonsense to say '70 percent of cognitive capacity is genetic' not just because of the point I made on this above (the 70 percent refers to variation) but also because cognitive capacity isn't a simple or purely physical thing. And it is just this that behaviour geneticists tend to glide over. Or worse, they presume an explicitly naturalistic framework.
Behaviour geneticists, in particular through their notions of evocative and active gene-environment correlations, tend to marry a naturalistic notion of potential to a statistical treatment of difference to produce the idea that genes play the active role in realising potential and difference. So in their new book on genetics and education, G is for Genes, Kathryn Asbury and Robert Plomin argue that 'the entire education system is predicated on the belief that children are "blank slates"', but that in reality it will soon be possible 'to use DNA chips to predict strengths and weaknesses for individual pupils'. (pp. 5, 12). What is needed, they argue, is learning that is 'personalised to an unprecedented extent', in a large and fantastically resourced school designed to 'activate positive genotype-environment correlations', so enabling children to 'fulfil their natural potential' (pp. 182, 183).
In summary: it is wrong to accuse Cummings and Plomin of 'genetic determinism' in relation to academic performance (of either schools or individuals). 'Genetic determinism' is consistent neither with Plomin's research findings nor with Cummings' policy proposals.
It's great to see Asbury and Plomin defying the current culture of austerity. But in their speculations about the prospects for 'personalised education' they exaggerate the grip of 'blank slate' thinking, introduce a naturalistic notion of 'potential' and go way beyond what is currently known about the character of causal contributions of genes to differences in cognitive ability.
John Gillott's book, The Changing Governance and Politics of Bioscience Research, is published by Palgrave Macmillan in Spring 2014.