Scientists have found 74 genetic variants that are associated with educational attainment. In short, that means some people have variants of genes in their DNA that are correlated with completing more schooling. But this finding, published today in Nature, should be taken with a grain of salt. Together, these variants explain less than half a percent of the differences in educational attainment seen in the population studied — far less than the impact that a person's wealth and environment can have on the time they spend in school.

They explain less than half a percent of the variation in educational attainment

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.

There might be "drugs that could affect some of these students"

The study is "outstanding," says Elliot Gershon, a psychiatrist and human geneticist at The University of Chicago. The findings don't explain a large portion of overall educational attainment, but the fact that these variants consistently explain some of it should force researchers to rethink how they can increase the years of schooling people complete. "For example, you might think about whether there are drugs that could affect some of these students and thereby improve cognitive educational attainment," he says.

Not everyone agrees with that view. "I mean, you'd get better results if you got the lead out of the water," says Arthur Caplan, a bioethicist at New York University. Looking at the genetics of human behavior is interesting but researchers already know what factors have a large impact on schooling, so it makes more sense to focus on that rather than the promise of a pill. "To me, the danger of these kinds of reports is that they divert from obvious huge causally important factors that drive ability to advance in school, like safe schools, enough teachers, classroom size, nutrition, lead — you can make a list!"

And besides, educational attainment isn't a good measure of intellectual achievement, Caplan says, because some forms of schooling are very different from others. "I'm not sure I fully support the utility or worth of this association because I don't think that particular measure is all that useful. It's too complex; it's not instructive," Caplan says. And even if the effects that the researchers had found were larger, "it's not clear what you do with them anyway."

"I am strongly against such analyses."

Caplan isn't alone in questioning the utility of the finding. In fact, one researcher said the study shouldn't have been conducted at all. "There are so many KNOWN and POTENT reasons why people don't achieve educational attainment that looking for genetic effects that are UNKNOWN and OF MINUSCULE EFFECT seems pointless [sic]," Aravinda Chakravarti, a geneticist at Johns Hopkins University, told The Verge. "I am strongly against such analyses," he said before declining to comment further.

Caplan doesn't go as far as that ("everything and anything about human beings should be subject to free inquiry," he says). But as far as the findings stand right now, they shouldn't be seen as much more than a curiosity. "It's interesting to try to examine the role that genes play in sort of controlling our hardware, which is the brain, relative to our behavior, but let's not forget what we know from common sense," he says. "What really drives intellectual performance, school achievement, and years in the school is culture, environment, budget — and pure luck as to where you're born. I wouldn't transfer these genetic enthusiasms into public policy."