It is very clear that the issue of heritability of IQ and educational achievement, and environmental effects on these, is extremely contentious, and it’s not too hard to cherry-pick the data to support whatever conclusion you like. That said, the idea that “Social class remains the strongest predictor of educational achievement in the UK”, as this paper by a professor of education points out, seems fairly well established. I accept that I might have missed some acknowledgement of this in Cummings’ book-length document to Gove, but if so, I’ll need to have it pointed out to me. I find it very hard to see how anyone reading Cummings’ paper would have come away with that impression – rather, he argues rather strongly that genes, not socioeconomic status, are the central determinant.
But his claims are stronger than that. I have been rereading this particular passage to see if somehow I have got the wrong end of the stick:
“Raising school performance of poorer children is an inherently worthwhile thing to try to do but it would not necessarily lower parent-offspring correlations (nor change heritability estimates). When people look at the gaps between rich and poor children that already exist at a young age (3-5), they almost universally assume that these differences are because of environmental reasons (‘privileges of wealth’) and ignore genetics.”
So what is Cummings implying here, if not that the differences in school performance between rich and poor children might be, at least in large part, genetic? That the poor are, in other words, a genetic underclass as far as academic achievement is concerned – that they are poor presumably because they are not very bright? I am trying very hard to square this idea with the statement by Turkheimer and colleagues (2003 – paper here) that “in impoverished families, 60% of the variance in IQ is accounted for by the shared environment, and the contribution of genes is close to zero; in affluent families, the result is almost exactly the reverse.” (Yes, Cummings alludes briefly to Turkheimer’s work, but only by linking to a blog that mentions it and only in order to dismiss it as largely irrelevant to the debate.) Cummings does not say that we should give up on the poor simply because they are genetically disadvantaged in the IQ stakes – but comments like the one above surely give a message that neither better education nor less social disadvantage will make an awful lot of difference to academic outcomes.
Cummings advocates the potential value of “finding the genes responsible for cognitive abilities”. The entire point of my article is to challenge the assumption that there are “genes for” cognitive abilities. I point out that a large group of the world’s top researchers on genetics and cognition has just conducted a big study to identify such “genes”, and finds that most of the previous candidates are illusory. They find three genes linked to variations in IQ, and these account for differences of at most just 1.8 IQ points and are in the authors’ words “not useful for predicting any particular individual’s performance because the effect sizes are far too small”. Of course, it may be that the key “genes for” just haven’t yet been found. Or it may be - and Cummings has evidently failed to grasp this central point – that because a trait is somewhat inheritable does not imply that there are “genes for” this trait in any meaningful sense. That is why I find his comments misleading.
A little bit of reading comprehension here. Cummings complains about my remark that “So it’s not clear, pace Cummings, what this kind of study [i.e. the one mentioned in the paragraph above] adds to the conventional view that some kids are more academically able than others. It’s not clear why it should alter the goal of helping all children achieve what they can, to the best of their ability.” He says “I did not make the argument he implies – i.e. we should ‘alter the goal of helping all children’…”. Does “it should alter” refer to (A) the aforementioned academic study; (B) Dominic Cummings’ paper; (C) Michael Gove’s MP expenses claim? The point here is not that Cummings doesn’t want all children to achieve what they can – I genuinely believe he does want that – but that it is not at all clear from current findings on genes and IQ that that research has much to offer the formulation of educational policy.
I’m less concerned about Cummings’ accusations of “unprofessional journalism, riddled with errors”, since he doesn’t really explain what these errors are. His advice to Prospect – “do not publish journalism on this subject without having it checked by a genuine expert” – is a bit of a hostage to fortune, given that my article was read by Steve Jones and a colleague of Robert Plomin’s, who found none of these “errors”. If you do want the opinion of another real expert, rather than mine (and who could blame you?), you might want to look at what Steven Rose has to say on the topic, and then decide if there is any daylight between that and this.