Using data from more than 3 million people, a team of researchers from the Social Science Genetic Association Consortium completed what is now the largest genetic study ever done on educational attainment, the measure of the number of years someone spends in school.
“Educational attainment is influenced primarily by institutional and environmental factors, such as socioeconomic status, school quality, and the neighborhood where you grow up,”said Aysu Okbay, the study’s lead author and an assistant professor at the Vrije Universiteit Amsterdam. “But psychological characteristics that are influenced by genes, including certain cognitive abilities and personality traits, also matter for school performance.”
It’s estimated that at least 20 percent of the variation in educational attainment between people can be traced back to genetic factors. But each genetic variant — each single nucleotide polymorphism or SNP — only has a minute influence. This illustrates “polygenic” influence on educational attainment, where no single common variant plays a large role.
Although this study found more than 3,900 SNPs associated with educational attainment, the researchers estimate that there are likely tens of thousands if not more that play a role. Taken together, the SNPs included in this study explain about 13 percent of the variance in educational attainment among people of European ancestry. In comparison, household income predicts about 7 percent of the variation in educational attainment, while a mother’s education level predicts about 15 percent, according to the researchers.
The genetic associations identified in this study, however, explain far less of the variance in educational attainment among people of non-European ancestry. Although this study included more than 2 million 23andMe customers who consented to participate in research, the researchers argue that an even larger study with a more diverse set of research participants would uncover more relevant genetic variants and be more relevant for people of non-European ancestry.
This is not the first time the consortium, which includes scientists from a dozen institutions around the world, has looked specifically at educational attainment. The last study, which had only a third as many participants and was published in 2018, found about 1,200 genetic variants that, taken together, suggested an association with brain development.
In a detailed document that accompanied the publication of the current study, the researchers explain that the connection to brain development isn’t likely to be a direct one. Instead, brain development affects psychological characteristics like cognitive performance and personality traits that in turn lead to behavioral tendencies. These tendencies, in combination with other factors, play a role in outcomes at school. For example, differences in school performance may relate to sleep quality, attention span, or personality traits. A student who is more willing to listen to a teacher’s instructions and gets a good nights rest might do better in an academic setting, for example.
Read the full paper here.