An international team of researchers has identified more than 1,200 genetic variants that are associated with how much schooling a person completes and used the findings to create a “polygenic” score that is predictive of more than 11% of the variation in education level between individuals.
The meta-analysis, which is published in the journal Nature Genetics, included data for more than 1.1 million people of European descent from 15 countries and is one of the largest studies of human genetics to be carried out to date.
The authors say that although the polygenic score is by no means deterministic, it does shed new light on how genes can influence complex behaviors.
"It moves us in a clearer direction in understanding the genetic architecture of complex behavior traits like educational attainment," says co-first author Robbee Wedow from the University of Colorado at Boulder.
For the study, which was led by the Social Science Genetic Association Consortium, Wedow and colleagues analysed information from 71 genetic datasets, as well as surveys assessing how many school years people (aged 30 or older) had completed.
The researchers identified 1,271 gene variants associated with educational attainment, including variants that are involved in inter-neuron communication and the secretion of neurotransmitters.
Wedow and team stress that single gene variants have little predictive value and that it would be misleading to characterize the results as identifying genes for education.
Taken together, the variants account for approximately 4% of the variation in the level of education individuals attain. However, when the researchers included the influence of the variants across the genome to create a polygenic score, that score could predict 11 to 13% of variation in the number of school years people completed.
That is a large effect for a polygenic score, especially for a behavioral outcome,"
Robbee Wedow, University of Colorado at Boulder
Wedow adds that, although the score is useful for research, it is by no means deterministic and that having a low score would not mean a person will not achieve a high level of education, since other factors such as socioeconomic status and ambition have a larger effect than genes.
However, it is useful for social and medical research looking at how the effects of genetic variants change across different environmental conditions. It could also help researchers gain insight into how educational attainment and associated outcomes are influenced by the interplay between genetics and environment.