Genes, ‘intelligence’ and our education

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In the fourth and final article of her series on the teenage brain and how it affects education, Dr Stephanie Thornton discusses the implications of what we know about ‘intelligence’.

We have learned a lot about genes in recent decades. It is no exaggeration to say that the educated reader today has access to more information about genetics than the top research minds had a mere 50 years ago. But what, exactly, do we all know – how accurate is our understanding?

‘It’s in the DNA’

That phrase is used as a metaphor to explain anything and everything. Everyone knows what it means: something so hard-wired into us as to be almost immutable. And that idea of DNA as defining our fundamental characteristics and potential is rampant in the popular press – hardly a week passes without some excited report of the discovery of the genes for this or that – from happiness to schizophrenia, musicality to intelligence...

This view of genetics as the driver of behaviour (crucially, of intelligence) is already raising questions for education. If it is all in the genes, then doesn’t it make sense to acknowledge that and to tailor education to a child’s genetic potential?

Last year a major report to the education secretary, Michael Gove, made just such a suggestion, arguing that we should invest in genetic research to identify the gifted, screen to pick them out and fast-track them for the good of the nation.

Other politicians picked up on this, suggesting that it makes sense to nurture the most able two per cent rather than “wasting resources” (as one Tory put it) on the 16 per cent with low intelligence.

This, of course, is where the debate about intelligence and education began. Galton’s early observations and a great deal of subsequent research demonstrated that there is a strong genetic basis for individual differences in intelligence.

In the early 20th century this discovery made it seem obvious to experts that education should be tailored to reflect the potential of the individual. The result was a split between schooling for the more able (creamed off into grammar schools), schooling for the average, and separate schooling for those of below average intelligence.

That early selectivity policy fell into disrepute for various reasons. Genetics became politically suspect, having been used to support various unsavoury and discredited political and racist philosophies. 

Then research on the genetics of IQ fell into disrepute: a leading figure was accused of using fraudulent data to prove the heritability of intelligence – on top of which, complex technical problems with the statistical methods used in measuring heritability made the whole issue controversial.

But what now? Today, powerful new methods allow us to decode genetic material, and to look for the effects of genes in ways undreamed of only a short while ago. There is a powerful public acceptance of genetics (it’s in our DNA, you might say). And it sounds so simple, doesn’t it? If intelligence is determined by our genes, then surely there is a case for using genetic testing to select individuals for different forms of schooling suited to their potential?

All that glitters...

Genetic research truly has made enormous strides in recent decades. The findings of this research do indeed have important implications for education. But those implications are not the ones that seem to follow from the popular mantra “it’s in the DNA”.

The problem is that the way genes function is far, far more complex than is generally supposed – and we know less about it than is popularly supposed.

Can we actually use genetic testing to identify an individual’s cognitive potential? The answer is no: what is clear from research is that the complex phenomena of intelligence do not reflect the action of single genes, nor even of a handful of genes: it seems likely that intelligence is the result of hundreds of genes in interaction, each contributing a tiny amount of the variance between less and more able individuals. We haven’t identified those genes, still less worked out how they interact.

If we had a genetic test for intelligence, would it actually allow us to predict an individual’s potential, and so justify offering different individuals different educational opportunities? The answer is no: it’s true that individuals with higher IQ tend to do better in school (but then, so do individuals from higher socio-economic backgrounds, or individuals from better schools).

But by no means every member of MENSA is a high flier; and some individuals with well below average IQ go on to achieve far more than was predicted for them. Predicting performance from IQ is not as accurate as many think. And all this supposes that a one-off genetic test could, even in principle, specify IQ...

In fact, neither genes, nor IQs are as fixed as is popularly supposed. At any one time, some of our genes are switched on, and others are switched off. What shapes all the complex processes that underlie our physiology and psychology are the genes that are switched on. And which genes are switched on is not fixed: genes can be switched on or off by life experiences of many different kinds, from exercise and diet to how we use our minds, what stressors we encounter and so forth. 

In sum: even what is effectively “in the DNA” is importantly shaped by the environment. We don’t yet understand exactly how this interplay between environment and genes affects intelligence – but we do now know that IQ can vary quite substantially over time within an individual: variations of 20, or even up to 40 points are not rare. 

Such changes may be in either direction, reflecting better or worse socio-economic, emotional circumstances, opportunities, expectation and tuition. Genes do not set a given level of IQ in stone.

In sum: Science has not discovered immutable differences in intelligence between individuals, fixed by their DNA. In fact, there is nothing in genetic research that mandates selectivity as the superior option in education: whether we hot-house the 

two per cent of the young who already find study most easy or invest more resources in supporting those who need more help is entirely a political decision. 

If recent research on intelligence research does not bear on the obvious issue of selectivity in education, does it have any practical implications for the classroom at all? The answer is yes. The implications are in the detail:

Classroom implications

  1. You can change your pupil’s IQ – maybe not a lot, but enough to make a difference. There is clear evidence that, when a child moves from a poor school to a good one, or receives better teaching, not only performance but general IQ rises. The longer the better provision lasts, the more IQ can increase.

  2. A teacher’s greatest impact is on the socially disadvantaged. Among the privileged, where all get the same excellent tuition, differences in IQ may be 70 per cent determined by genetics. But among the disadvantaged, only 10 per cent of the variance in IQ between individuals is genetic; socially disadvantaged environments undermine the child’s potential. The more such a child’s experience can be enriched by a good teacher, the greater the possibility for intelligence to develop.

  3. Genetics makes the case for personalised teaching The discovery that intelligence is the product of hundreds of complex gene interactions emphasises the sheer variety of individual minds. Intelligence is not “one-size-fits-all”, so nor is optimal teaching. The ability to use genetic code to design personalised teaching is far, far away. Luckily we don’t need complex genetic tests to tailor teaching to an individual’s needs: only commitment, existing skills and the resources to do so.

 


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