10 August 2015
Guardian Science Weekly, Friday 17 July 2015
Presented by Dr Ian Sample
In a question almost certain to raise the hackles of people who read too much dystopian fiction, Science Weekly host Ian Sample asks, 'Can genetic screening help children perform better at school?' Wading into such murky territory on this episode of the Guardian's podcast is Professor Robert Plomin, who researches the genetic basis of academic achievement at King's College London.
More accurately, Professor Plomin looks at how differences in people's genes are associated with differences in their intelligence, most often measured as differences in test scores. He is a behavioural geneticist, which technically means he's a psychologist, not a geneticist, and much of his work has involved studying twins, assuming they are influenced in the same way by their shared environments – from wombs to classrooms. Professor Plomin and colleagues use this information to try to tease apart the effects of genetics and environments. The more that genes influence academic performance, the higher a measure called heritability.
Two weeks ago, his team published a study saying that around 60 percent of the differences between teenagers in their GCSE results can be explained by the differences in their genes (see BioNews 812). Their other work, discussed in this episode, has come to the surprising conclusion that this level of heritability remains the same from primary school through to A-level and across all subjects, from maths and the sciences through to art and the humanities.
Although it sounds simple, heritability is actually an enormously abstract and unintuitive idea. It tells us something about how differences in genes can lead to differences between people in a population – although you might normally conceive of genes as something belonging to and building individual humans. I find this hard to get my head around, even though my day job involves thinking about evolution – something that happens to populations – and doing statistics (don't tell my boss).
In the podcast, Professor Plomin makes it clear that his research tries to explain the differences between children in terms of the differences in their genetics and their environments, rather than attempting to explain any one child's predilections due to her genes or school. He explains heritability better than most, but still he can't avoid using statistical terms like 'mean' and 'variance'.
'Our way of thinking about education is screwed up because we don't take genetics seriously,' he asserts. We need to help teachers and politicians understand these concepts. Perhaps the audience of Science Weekly are a little more au fait with statistics than your average (or 'mean', if you fancy a stats pun) person on the street, but in a week where the British Academy has bemoaned the UK's lack of numeracy, I don't think he can assume that all listeners are going to be familiar with these technical terms.
Despite the high heritability of exam results, no one yet knows which genes affect a person's academic performance (this is called the 'missing heritability problem'). As genetic screening is nominally the subject of this podcast, host Ian Sample asks how we can screen children if we don't even know what we're looking for. Plomin's hand-waving answer to this is, essentially, 'We're working on it.'
There is a broader issue, as the Guardian's science correspondent and co-host Hannah Devlin points out: we should ask what we want from education, ask what schools are for and whether we should try to get all children up to the same level of education.
When all children are given the same opportunities, the environment has an equal influence on their achievements, meaning that the only differences between children will be due to genetic differences – heritability will be 100 percent. So, by Professor Plomin's reckoning, 'heritability is an index of equality'. He also argues that children with different genetic propensities might take different advantages of the same environment.
It is around these topics that Professor Plomin's passion really shines through. He argues for an education system based on 'appetite and aptitude', where we 'find out what children like to do as well as what they're good at'. He rails against the quixotic desire for silver-bullet fixes and unproven gimmicks and is all for evidence-based education policy, saying it's 'abysmal, appalling that we don't use evidence as the ultimate arbiter' for whether policies work.
He points out that we spend as much on education as we do on health and therefore we should 'hold education to the same standard as medicine', not least because both, if done inappropriately, can lead to lasting damage.
Medicine has for decades prized evidence from rigorous experiments. Evidence-based medicine has become the norm and we'd consider it dangerous if treatments hadn't been put through trials. As comedian Tim Minchin says (read this in an Aussie accent): 'Do you know what they call alternative medicine that's been proved to work? Medicine'.
Maybe one day we'll be able to call evidence-based policy in education simply 'policy'.