News in Science

Degrees of learning in the genes

'Smart' gene It's not quite the 'smart gene' but researchers have identified a small number of genetic markers associated with educational attainment.

A genome-wide association study using genetic data from more than 100,000 individuals found three genetic markers that were significantly linked to an individual's numbers of years of schooling and highest degree of education.

The results of the Social Science Genetic Association Consortium study, which includes 128 research organisations and universities worldwide, are published today in Science.

While the individual effects of each of the genetic markers was very small -- less than 0.02 per cent -- co-author Professor Peter Visscher says this is not unexpected for a trait as complex as educational attainment.

"We know from twin and family studies that most variation in a trait like educational attainment is environmental but there is also about 40 per cent of individual differences that seem to be due to genetic factors," says Visscher, professor of quantitative genetics at the University of Queensland.

"[These effects] are not inconsistent with diseases which also have a similar strong influence from the environment; for example, the heritability for major depression is also about 40 per cent and there also, the effect sizes are tiny."

Largest study

Researchers examined hundreds of thousands of genetic markers from people around the world, in one of the largest studies of its kind.

The markers they identified as being significant came from genetic regions that had previously been associated with health, cognitive function and central nervous system function.

"In my view, these are clearly a proxy for some underlying brain process, something to do with memory and learning," Visscher says, however it's a far more difficult task to work out the precise function of the genetic markers.

The study attempted to control for possible confounding factors such as socioeconomic status by examining the effects of the loci within families.

"In that case, the variation explained by taking all these markers together is still very small but it was statistically very significant, and within a family, it's very very unlikely that it would be confounded with anything," Visscher says.

The researchers were also careful to point out that they are not suggesting a person's educational achievements are all down to their genes.

"For most outcomes that we study as social scientists, genetic influences are likely to operate through environmental channels that are modifiable," says co-author and New York University sociologist Professor Dalton Conley.

"We have now taken a small but important first step toward identifying the specific genetic variants that predict educational attainment," says Conley.

"Armed with this knowledge, we can now begin to examine how other factors—including public policy, parental roles, and economic status—dampen or amplify genetic effects and ultimately devise better remedies to bolster educational outcomes."

The findings can also contribute to our understanding of diseases where these same processes may be faulty or failing, says Visscher.

"We are particularly interested here in cognitive ageing and ultimately dementia," says Vissher.

"So one idea is to study the disease itself, but you can also get in from the other end, [examining] what explains normal variation between people in learning and memory and how and why this is correlated with what happens to you later in life."