Researchers at King’s College London analysed thousands of study participants to unpick the contribution DNA and other factors, such as home life, make to higher education success.
After previous work by the group revealed a genetic influence on GCSE results, they say this is the first study to show a similar effect later in life.
The researchers found 57 per cent of the differences between people’s A-level results were determined by genes, with 46 per cent of achievements at university also dependent on their DNA.
The rest of the variation in results can be put down to students’ environments – everything from parents’ wealth to the quality of an individual’s schooling.
Besides exam results, genetics also appear to steer students’ desire to pursue a university education in the first place – with roughly half of the decision to go to university guided by DNA.
Dr Emily Smith-Woolley, who led the study, said the findings should have implications for students and teachers.
“Knowing that the difference between us in our university achievement is partly due to genetics is interesting and important, anyway,” she told The Independent.
“But from a teaching perspective, you don’t expect your students to all get it straight away – some will struggle, some will find things difficult, and it’s important to know that is not all to do with environment. People start off in different places.”
The scientists came to their conclusions by studying 3,000 pairs of British twins – identical and non-identical.
“Identical twins are 100 per cent genetically identical, they are clones of one another, so they share all their DNA and they share a home environment – so any differences between identical twins can’t be due to their home environment, can’t be due to their genes,” said Dr Smith-Woolley.
Comparing identical and non-identical pairs of twins enabled researchers to measure the overall impact of genetics on how much people differ when it comes to measures such as exam scores.
If identical twins’ exam scores are more alike than non-identical twins’, it is an indication genetic factors are driving that success.
Using Complete University Guide rankings to determine institution quality, the scientists also found the quality of university that students opted for was influenced by genes, even after accounting for A-level achievement.
Besides their twin study – which is not able to identify specific genes linked to achievement – researchers also calculated “polygenic scores”, adding up the effects of thousands of DNA variants previous studies have linked to success in education.
The resulting scores accounted for a small fraction of the differences between people, compared to the results of the twin study – an effect the scientists think results from the small number of genes so far linked with educational achievement.
“We found that, at the moment, polygenic [scores] showed up to 5 per cent of the individual differences in university success measures,” said Dr Smith-Woolley.
“That’s fairly small at the moment … but I think it shows that science is getting to the point where it can start predicting outcomes from DNA alone.”
The results were published in the Scientific Reports journal.
Dr David Hill, a statistical geneticist at the University of Edinburgh who was not involved in the study, said the research was sound, but perhaps not surprising.
Scientists think most behaviours are probably the results of a complex interaction between genes and people’s environments.
Considering previous research that has demonstrated the way in which educational success appears to be inherited within families, he said it was already clear there is a genetic component.
“I don’t really think anyone would expect there to not be a genetic influence acting on university success,” he said, “given that all traits are expected to be somewhat heritable, and we already know that educational success, intelligence, personality, and whether or not one chooses to take university entrance exams and how well they do at them, have all been shown to be heritable.”
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