Does DNA contribute to school performance?
To what extent does your DNA contribute to what you achieve in the classroom? Speaking with Chris Smith, Tim Morris explains how he has been trying to find out…
Tim - We have lots of information on why people perform the way they do in school. There's lots of background social reasons, parental reasons, there's intelligence and personality, and there's also an increasing argument that genes are really quite important for the way we learn amongst many other outcomes.
Chris - People obviously say, you know, bright kids tend to have bright parents, so that must be genetic. Of course, there's also the explanation that if you've got bright parents, you probably grow up in a household that's more educationally rich.
Tim - Yeah, that's right. There's probably some genetic components of it. But as you say, parents who are better educated are more likely to have more books in the household. They're more likely to take their children on museum trips or help out with their homework. So these things can operate kind of through both genetic and non-genetic pathways.
Chris - So how did you try and dissect apart the two?
Tim - So in our study we looked at the DNA of a sample of children from a UK cohort study called the Avon Longitudinal Study of Parents and Children, which has collected data on almost 15,000 children since the early 1990s. They've genotyped the children, and as a result of this, we know the parts of the DNA that they carry that may be related to things like educational attainment. And so we can build these genetic scores which provide a measure of kind of known genetic liability to a certain characteristic, in this case education. These genetic scores, they are called normally distributed. So some people score very highly, some people score very low or the bulk of people kind of are in the middle. And we're looking at how the differences on these genetic scores amongst the study children, how they relate to differences in exam performance throughout their schooling.
Chris - What did you find? Is there a really strong correspondence or not?
Tim - Well we find that on average, children with a higher genetic score tend to perform better than children with a lower genetic score. This is when we look at the population of children all together. But when we're looking at individual children, when we're interested in trying to predict how well a child will perform later in education, we see that at that individual level, these scores really aren't very useful.
Chris - Do you mean as in that there are no specific markers that you could say if you've got this particular makeup, you're going to be Einstein and if you haven't, you're going to do less well? It's not as predictive as that?
Tim - No, absolutely not. So one of the interesting things with things like educational attainment is that they are characterized by lots of tiny, tiny, tiny genetic effects. So there's no such thing as a gene for education or a gene for intelligence. We're seeing that there's combinations of thousands upon thousands of individual points of DNA that are very slightly related to educational performance.
Chris - So what's the take home message then?
Tim - I think the take home message is that that genetic data is really useful for asking and answering some questions on groups of people. But it's really not very useful, certainly with things like education, for predicting individual performance. So the idea of personalized education based upon genotype - we really don't see any evidence for that whatsoever.
Chris - So if it's not genes, what is it that determines a person's aptitude to learning and becoming very educated?
Tim - It's a whole complex range of things and this is the problem with the genetic prediction is that education is an incredibly complex characteristic. It's influenced by genes, by your intelligence, by your work ethic, by your parents, social class, by your parent's education, family structure, and there's so many different things feeding into education. It's completely unsurprising that using any one of those components will not give you a reliable prediction of how well a child will do. And you know what we've seen and what a number of studies have shown is that even when you're combining all of these different parts of information, it's still incredibly difficult to predict how well someone will do. There's too many unexplained factors and too much randomness, kind of inherent noise, in how well people perform.
Chris - Is that what you expected to find or were you hoping, when you launched into this study, that what was going to emerge was this really strong genetic predictor of education and you're going to go, there you go, this is the genetic hand you need to be dealt do well in school.
Tim - No, it wasn't that surprising to me. One of my motivations was to kind of stem the push that there's been from some scientists and nonscientists, including government advisors, that genetic data will be really useful for useful in schools for predicting how well children will do. So we weren't surprised to see that this wasn't the case. If anything, it was surprising to see just how little people's genes kind of, you know, their genotype, gave to the prediction of education. It really is, on top of everything else, almost nothing.