"Children differ in how easily they learn at school. Our research shows that differences in students' educational achievement owe more to nature than nurture," lead researcher Nicholas Shakeshaft, a Ph.D. student at the Institute of Psychiatry at King's College London, said in a college news release.
His team compared the scores of more than 11,000 identical and non-identical twins in the United Kingdom who took an exam that's given at the end of compulsory education at age 16.
Identical twins share 100 percent of their genes, while non-identical (fraternal) twins share half their genes, on average.
The study authors explained that if the identical twins' exam scores were more alike than those of the non-identical twins, the difference in exam scores would have to be due to genetics, rather than the environment.
For English, math and science, genetic differences between students explained an average of 58 percent of the differences in exam scores, the researchers reported. In contrast, shared environments such as schools, neighborhoods and families explained only 29 percent of the differences in exam scores. The remaining differences in exam scores were explained by environmental factors unique to each student.
Overall, genes had a greater effect on differences in grades in science topics such as biology, chemistry, physics (58 percent) than in subjects such as media studies, art and music (42 percent), according to the study published Dec. 11 in the journal PLoS One.
None of this means that students are destined to excel or doomed to fail, based solely on their DNA, Shakeshaft said.
"Since we are studying whole populations, this does not mean that genetics explains 60 percent of an individual's performance, but rather that genetics explains 60 percent of the differences between individuals, in the population as it exists at the moment," he explained.
"This means that heritability is not fixed -- if environmental influences change, then the influence of genetics on educational achievement may change too," Shakeshaft said.
While the findings may have no implications for educational policy, it's important to understand the important role that genetics plays in children's success at school, added study senior author Robert Plomin, of the Institute of Psychiatry at King's College London.
"It means that educational systems which are sensitive to children's individual abilities and needs, which are derived in part from their genetic predispositions, might improve educational achievement," he said in the news release.
The U.S. Centers for Disease Control and Prevention outlines the link between student health and academic achievement.