School serves two important functions in society. Firstly, it equips children with the knowledge and skills essential for them to successfully participate in society, for example, reading, writing and arithmetic. And secondly, school performance functions as a gatekeeper regulating children’s access to further education. That is, children who perform poorly in school are less likely to secure a place at university or other higher education institutions that place great demands on learning ability, compared to children who did well in school.
Children differ in school performance. This is true for all countries and education systems globally (see figure below). These differences are heritable: about half of the differences in children’s school performance can be attributed to genetic influences.
This figure shows the difference between the top and the bottom 10% of performers in PISA across OECD countries in 2015.
Genetic influence is caused by many thousands of DNA variants, each with a very small effect, that we inherit from our parents. These variants can be identified in genome-wide association studies (GWAS) that test the link between DNA and a target phenotype across the human genome in very large samples. For example, a study tested associations between DNA variants and how many years a person had spent in full time education in a sample of 1.1 million individuals (Lee et al., 2018). The identified DNA variants can be aggregated into so-called genome-wide polygenic scores that capture a person’s individual genetic predisposition for learning.
In a recent study, we used genome-wide polygenic scores for learning and measures of family background to predict children’s differences in school performance from age 7 to 16 years. We found that 27% of the differences in children’s school performance over time can be attributed to their inherited DNA differences and their family background. That’s a lot of variance explained by factors that can be assessed at birth, long before children even set foot into a school. The full paper is here: https://www.biorxiv.org/content/10.1101/538108v2
We are currently studying the interplay between inherited DNA differences and environmental factors in the prediction of educational achievement. We are looking forward to hearing from potential PhD students interested in this topic.