Australasian Science: Australia's authority on science since 1938

Gene Variations Influence Education

By Stephen Luntz

An exceptionally large study of single nucleotide polymorphisms (SNPs) – variations in which just one of the four nucleotides of DNA is altered – has found a number that relate to the time spent in education.

“We studied the genetic information of more than 125,000 people, looking specifically for SNPs,” says Prof Peter Visscher of the Queensland Brain Institute. The sample size was reached by combining the results from numerous other studies where genetic data was mined for the sources of physical illnesses.

No single SNP determines intelligence, but when a number were combined they were found to account for 2% of the difference in time spent in education and performance on intelligence tests.

Visscher says his own interest is in finding SNPs that might contribute to early mental decline, but to do this it helps to find the factors that lead to intelligence in the first place.

“Using twin studies we have found that around 40% of education attainment is determined by genetics, while in more direct studies, such as of intelligence tests, it seems to be 60%,” Visscher says.

However, identifying which particular genes are responsible is much harder, as demonstrated by the small proportion explained. “If we took the sample size up to a million we would find more genes and explain a larger portion of the variation, but there is still plenty that is environmental.”

The sample was drawn from the US, Europe and Australia, but Visscher says a deliberately homogeneous ethnic subset was used to simplify the variation. He also adds that while the sample was “not selected with respect to socio-economic group” it would have excluded anyone with rare but severe SNPs related to mental retardation.