Genetics and academic success at university

From time to time, these GEITP pages feature one or another genome-wide association study (GWAS). A genotype-phenotype association can be virtually anything that the scientific group decides to study. In the present case, genes [examining several million single-nucleotide variants (SNVs) across most of each individual’s genome] that show a statistically significant (P <5.0 x 10–8; also written as P <5.0e–08) correlation to the phenotype (trait) of "academic success" –– was searched for. In a way, this trait is less diffuse than trying to determine "degree of schizophrenia" or "degree of major depressive disorder", which truly represent vague gradients. The phenotype of academic success (measuring the level of education achieved) would be termed a "quantitative trait." The difference in earnings between high school and university graduates is estimated at $1 million over the course of one's lifetime. However, the difference in earnings varies by the type of university attended, as well as achievement at any university. Moreover, the benefits associated with obtaining a university education extend beyond earnings –– to include better health and well-being, higher rates of employment, and even an increased life expectancy. Despite this, little is known about the causes and correlates of differences in university-level outcomes, including entrance into a university, achievement at the university, and the quality of university attended. Differences in who obtains a university degree and who does not are, at least in part, associated with differences in prior academic achievement. Many quantitative genetic studies have shown that achievement in childhood and adolescence are substantially heritable, with 40 to 60% of the individual differences in achievement due to genetic factors. However, there are few studies looking at the heritability of academic achievement beyond compulsory education. Capitalizing on both quantitative and molecular genetic data, authors [see attached article and 15 pages of supplementary data] performed the first genetically sensitive investigation of "university success" with a UK-representative sample of 3,000 genotyped individuals and 3,000 twin-pairs. Twin-pair analyses showed substantial additive genetic influence on "university entrance exam achievement" (57%), "university enrollment" (51%), "university quality" (57%), and "university achievement" (46%). Authors found that environmental effects tend to be non-shared –– although the shared environment is substantial for university enrollment. Furthermore, using multivariate twin-pair analysis, authors showed moderate-to-high genetic correlations between university success variables (0.27–0.76). Analyses using DNA alone also supported genetic influence on university success. For example, a genome-wide polygenic score, derived from a 2o16 GWAS of "years of education" predicted up to 5% of the variance in each university success variable. These data suggest that young adults select and modify their educational experiences, in part, based on their genetic propensities. These findings also highlight the potential for DNA-based predictions of real-world outcomes, which will continue to increase in predictive power in the future. [For anyone interested, two press releases are pasted below.] DwN Sci Rep (Nature) 2o18; 8: 14579 University choice and achievement partly down to DNA Research from King’s College London has shown for the first time that genetics plays a significant role in whether young adults choose to go to university, which university they choose to attend and how well they do. Previous studies from King’s College London have shown that genetics plays a major role in academic achievement at school, with 58% of individual differences between students in GCSE scores due to genetic factors. However, there are few studies looking at genetic influences on academic achievement beyond school education. Using data from the Twins Early Development Study, funded by the Medical Research Council, the researchers found that genetic factors explained 57% of the differences in A-level exam results and 46% of the difference in achievement at university. They also found genetics accounted for 51% of the difference in whether young people chose to go to university and 57% of the difference in the quality of the chosen university. Dr Emily Smith-Woolley, from the Institute of Psychiatry, Psychology & Neuroscience (IoPPN), who co-led the research said: ‘We have shown for the first time that genetic influence on educational achievement continues into higher education. Our results also demonstrate that the appetite young adults have for choosing to continue with higher education is, in part, influenced by their DNA.’ The researchers also found that shared environmental factors – such as families and schools - influenced the choice of whether to go to university, accounting for 36% of the differences between students. In a previous study, the researchers also found shared environment accounts for almost 40% of the differences in whether students chose to take A-levels. However, shared environmental influences appear to become less important over time for educational achievement. While shared environment accounts for up to 20% of differences in achievement in secondary school, the researchers found the influence of shared environment dropped off for achievement at A-levels and was negligible for achievement at university. Dr Ziada Ayorech, from the IoPPN, who co-led the research said: ‘Unlike secondary school, where students tend to share educational experiences, university provides young people with greater opportunity to be independent and to carve out their interests based on their natural abilities and aptitudes. Students’ unique environments – such as new friends, and new experiences – appear to be explaining differences in university achievement and the role of shared environment becomes less significant.’ Interestingly, differences in the quality of university young people chose was strongly influenced by genetics (47%) even after accounting for A-level achievement, suggesting factors other than ability play an important role in university choice. University quality was assessed using the ‘Complete University Guide’ rankings for the year in which the students entered university. The results were based on studying 3,000 pairs of twins from the UK as well as 3,000 genotyped individuals. Comparing identical and non-identical twin pairs allows researchers to determine the overall impact of genetics on how much people differ on measures like exam scores. If identical twins' exam scores are more alike than those of non-identical twins this implies the difference between twin pairs is due to genetic factors Twin studies are not able to identify specific genetic variations which are linked to educational achievement. Nonetheless, the researchers were able to demonstrate a small genetic effect on university success just using DNA from individuals. They used ‘genome-wide polygenic scores’, which add-up the effects of thousands of DNA variants which have previously been linked to educational success in large genetic studies. Genome-wide polygenic scores only explained a small fraction of the differences in A-level exam results, university achievement and young people’s choices in higher education, and not the higher percentages identified from comparing twins. The researchers say this discrepancy is because much larger genetic studies are needed to identify more DNA variants linked to educational success. The results were published in the journal Scientific Reports. Nature Press Release: Scientific Reports [2] Genetics: Genes may influence university choice and achievement Genes may, in part, influence young adults’ decision to go to university, which institution they attend and how well they do, according to a study in Scientific Reports. Ziada Ayorech and colleagues analyzed genetic information from 3,000 individuals and 3,000 twin pairs to examine the extent to which genes explain differences in measures related to university education between young adults. By comparing identical and non-identical twins, the authors found that genetic factors explained 57% of the differences in A-level exam results (used to determine university entrance in the UK), 51% of the difference in university choice, 57% of the difference in the quality of the chosen university (as measured by factors including academic reputation and employment prospects), as well as 46% of the difference in achievement at university. Previous studies have shown that genetic factors explain a substantial amount of the differences between students' educational achievement in primary and secondary school. However, the authors suggest that this genetic influence continues into university. They argue that this may be because university allows students freedom to choose classes and environments based on their genetically influenced aptitudes. Furthermore, they found that, although the ‘shared’ environment, such as family or school, influenced the decision to go on to university, it was individual or ‘unique’ environments that explained part of the differences in university achievement. As well as using twins to untangle the genetic and environmental influence on measures of university success, the authors also used DNA alone to show that university success was influenced by genetics.

This entry was posted in Center for Environmental Genetics. Bookmark the permalink.