In fact, the researchers stressed in an email to The Verge that the strongest association found for a single genetic variant explained only 0.035 of one percent of the variation in educational attainment. “Put another way, the difference between people with zero and two copies of this genetic variant predicts, on average, about nine extra weeks of schooling,” says Dan Benjamin, a behavioral economist at the University of Southern California who worked on the study. These variants don’t mean much when it comes to people’s schooling, and factors like poverty, geography, and nutrition probably have a much bigger combined impact. So what’s the point of studying these variants if scientists already know about other factors that have a large impact on educational attainment?
The researchers say this information is valuable because it might help us better understand how our genes are impacted by our environment. But other experts aren’t convinced that this association should be viewed as anything more than a factoid — and some think the research shouldn’t have been done at all.
In the study, the researchers define educational attainment as the number of school years that a person completes. To study how this is linked to genetics, the team looked at the genomes of nearly 300,000 individuals of white, European descent and tested statistically whether, on average, people with one version of a genetic variant ended up completing more or less school than people with another version of the genetic variant. Then, the scientists verified their findings by replicating them in 111,000 individuals who took part in the UK Biobank, a large and ongoing health study. Through this analysis, the researchers found 74 genetic variants that, when combined, can be used to explain about 0.43 percent of the variance in schooling seen across individuals — an extremely small effect.
Still, the researchers think understanding these variants — and millions of others like them that may be discovered later — could be valuable. That’s because knowing how genetics impact education might help scientists better separate the effect of those genes when they’re trying to estimate the impact of social interventions.
The researchers also point out that some of the variants associated with higher educational attainment had previously been linked to brain development before birth, bipolar disease, Alzheimer’s disease, and schizophrenia. So studying these genetic variants lays the groundwork for future research that not only looks at how genes interact with the environment, but also at how genes that play a role in education overlap with those involved in these health conditions.