Lee Elliot Major argues that genes matter, but environment and education do too.
‘Success DOES depend on your parents’ intelligence: Exam results are influenced by genes, not teaching’, was the dramatic headline in the Daily Mail. The article claimed that ‘inherited intelligence could account for nearly 60 per cent of a teenager’s GCSE results.’ It was one of several sensational pieces penned in the wake of a recent interview in the Spectator magazine with the behavioural geneticist Professor Robert Plomin.
I have no doubt that genes impact on how well we do at school among much else in our lives (particularly worrying for me is the strong biological link in our body mass index – an association that gets stronger as we age). But a gentle probing beneath these bold claims reveals a much more complex picture of the forces that shape us all.
A balanced reading of the evidence suggests that there is plenty of space for teaching in general and the work of the Sutton Trust in particular to have an impact on children’s life prospects. Yes genes matter; but environment and education do as well. Two decades on from the American Psychological Association’s declaration that nature and nurture contribute in equal measure to who and what we are, I see no reason to disagree with this judgement.
Here are seven reasons why:
1. Heritability is not a measure of genetic inheritance
Plomin’s studies focus primarily on a concept called heritability. I won’t delve into the details here, but all you need to know is that the headlines are basically misleading. Heritability is not actually a measure of the extent to which traits are genetically transmitted from one generation to the next. It is an estimate of how much of the DIFFERENCES in traits across a population are due to genetic rather than environmental factors. These are very different things.
Click here for an explanation of what heritability is, and what it isn’t.
2. Twin studies make lots of assumptions
These estimates come from twin studies, which like all research are based on assumptions. Lots of them. One of the most contested is the ‘equal environments’ assumption. In short, can we really say without any doubt that the way in which two genetically identical twins interact with the world around them is exactly the same as that for non-genetically identical twins? If the answer is no, as many believe, then the conclusions over-estimate the importance of genes. See this academic review.
3. Other studies reveal little impact of genes on cognitive tests
Other studies that have investigated particular genes associated with intelligence have failed to find much if any biological impact on cognitive tests. Check out these conclusions from two hard nosed economists: “Our results suggest that the leading candidate genes can jointly explain just 2% of the socio-economic gap in children’s reading test scores… We conclude that the influence of these three genes on children’s reading ability is limited, and their role in producing socio-economic gaps in reading ability is even more limited still.” Here’s a summary.
4. IQ matters only so much for educational and life outcomes
I can understand why academics are pre-occupied with intelligence. But for the rest of us in the ‘real world’, there is an appreciation that success in life is not just about being clever in this narrow sense. Read Malcolm Gladwell’s book, Outliers, for a compelling case on why we need only so much IQ to get on in life. It is practical and personal skills that matter just as much. And these attributes are less associated with genes, and shaped more by the world around us.
5. Environment matters more for poorer children
This is a really important point. One of the concerns of the Trust is the ever widening gap in resources devoted to education between the privileged and not-so-privileged. Observe the phenomenon of private tuition for example. Middle-class parents will do all they can to ensure their children do well academically, irrespective of their innate abilities.
The flipside to this is that IQ exhibits a weaker link with the life outcomes for children from poorer homes who do not benefit from all this help.
And this is exactly what a forthcoming paper by the world-renowned sociologist, John Goldthorpe, will show. Children of similar cognitive ability but different social origins have very different chances of educational success. That is why we need Sutton Trust programmes so academically talented children from low and middle income backgrounds can fulfil their true academic potential.
6. Genes versus environment is a false dichotomy
Always beware the false either/or debates in education. And this almost certainly applies here. Lots of leading academics have argued that the whole idea of splitting traits such as IQ into separate components of heredity and environment is scientifically indefensible: we are the product of the complex dance in gene-gene and gene-environment interactions from the womb onwards. See Heckman on this.
7. We should focus on what could be not what has been
Finally, all this research is based on what has been, not what could be. There is increasing recognition among educationalists that great gains could be made if we could help more teachers meet the very best standards in classroom teaching. In the great nature-nurture battle, there is a lot more nurturing that could be done.