Maybe our genes help shape the environments we make for ourselves and our children
During the past century, genetic research on intelligence was in the eye of the storm of the nature–nurture debate in the social sciences. Much of this debate has been ill tempered and polarized.
Back in October 2017, Toby Young, who recently resigned from the New Schools Network, pointed out that the strongest single predictor of how well children do in their GCSEs is IQ, with differences in children’s general cognitive ability accounting for more than half of the variance in exam results. His observations were controversial. So much so that Teach First decided to remove his blog, articulating these claims, from its web site. Controversial, not so much in the sense that there is no science to back these claims, because there is (though contested) , but because of the politics. The Left and Right have very different views on the influence of genes and heritability and of the respective impact of nurture and nature on social and educational outcomes. The Right says that genes are much more important than is currently acknowledged in pre-determining outcomes, the Left says that too much weight is given to nature, rather than nurture, which downplays the importance of interventions to secure better outcomes and equity.
Young went on to say that children’s genes account for between 60 and 70 per cent of the variance in GCSE results, with IQ responsible for about half that genetic influence. But that still leaves the environment (including the school environment) accounting for between 30 to 40 per cent. Young argued that he was attempting to show how teachers could remain’ evangelical about raising standards’ without denying the mainstream scientific understanding about the heritability of IQ and the impact of IQ on educational outcomes.
Young’s views are similar to those of Professor Robert Plomin (he has worked with Plomins team) , an American psychologist at Kings College, London, also a controversial figure, who has long championed the idea that intelligence is highly heritable. Plomin set out his own philosophy in a recent review paper published in January (see the link below). In short, he claims that life is an intelligence test, and this trait predicts better than any other how your life will turn out. During the school years, differences in intelligence are largely the reason why some children master the curriculum more readily than other children. Children have an endowment of genes and it’s the purpose of education to maximise the potential of that endowment. The reality is that a large proportion of the differences in outcomes at school are caused by genes. So, Intelligence is highly heritable, and, moreover, predicts important educational, occupational and health outcomes. Better than any other trait. As far as evidence is concerned bigger and better family studies, twin studies and adoption studies have amassed a mountain of evidence, he says, , that ‘consistently showed substantial genetic influence on individual differences in intelligence Meta-analyses of this evidence indicate that inherited differences in DNA sequence account for about half of the variance in measures of intelligence’. Intelligence is not the same as your level of education, but it influences it.
This argument ,though, goes down like a lead balloon with those who start from the premise that most children are blank slates that have equal potential when they enter school.
The technology involved in reading the human genome is much more advanced now than it was, even five years ago. We are now entering a new era of biological revelation thanks to “genome-wide association studies” These involve sequencing the genomes of tens or even hundreds of thousands of people, and then scanning for particular genetic variants that are common to people who share a specific characteristic. This is allowing Prof Plomin, and others, to gradually plot the genomic co-ordinates of their chosen characteristic: in this case intelligence. Although its worth pointing out that there is no such thing as a “gene for intelligence”; rather, it is a composite of hundreds, perhaps thousands, of genetic variants.
Now, Genome-wide polygenic scores (GPSs) for intelligence can aggregate the effects of these thousands of DNA variants associated with intelligence across the genome.
Intriguingly, just published research from Kings College finds that there are, on average, measurable genetic differences between students attending different types of schools. Pupils from selective schools were compared to pupils from non-selective state schools. By linking genetic data from nearly 5,000 pupils to exam results, researchers London found “an association between genotype and school type” that could account for why children at selective schools notch up higher scores. (so, its not really about selective schools adding value)
Writing in the FT this month, science journalist Anjana Ahuja suggested that educators should take heed of these revelations.
She wrote ‘ Academic achievement is generally seen as a product of environment: having affluent, educated parents; living in a book-filled home; being fed a nutritious diet; attending top schools. But these environmental factors are tied up in genetics too, in a circular phenomenon that goes by the name of gene-environment correlation. We traditionally think of genes and environment as largely separate entities that combine to create our wins and losses, but there is growing evidence that our genes shape the environments we make for ourselves and our children.’
The trouble is that this issue, along with the science and the politics that go with it, means that discussions become ,in short order, not entirely rational. Cognitive biases intrude and the quest for truth becomes something of a side issue. But its right to take a closer look at the science and seek empirical evidence. It could help us better understand how to achieve the best outcomes for our children. It is important to face whatever science will reveal without prejudging the outcome and with the confidence that we can be mature enough to handle any findings. And hopefully use them to good effect.