A worldwide consortium of medical researchers and social scientists has found tiny changes to a person’s genetic sequence are associated with educational level.

The study was conducted by the Social Science Genetic Association Consortium, which includes Professor Peter Visscher.

“We studied the genetic information of more than 125,000 people, looking specifically at a type of genetic variation called single nucleotide polymorphisms (SNPs),” Professor Visscher said.

A SNP is one of the most common genetic changes and involves the replacement of a single unit that makes up our DNA with another.

“We investigated whether any of these small genetic changes were associated with the number of years of schooling and also whether or not a person had finished tertiary education,” he said.

The study identified a number of SNPs that, when combined, were found to account for around two per cent of the difference in number of years and cognitive ability of the individuals.

Professor Visscher explained that although this finding is only a very small piece of a very large puzzle, involving many other genetic and environmental factors, it does have a number of significant implications.

“These small changes, though they have little effect alone, may lead to insights into biological pathways underlying human behaviour.

“Discovering them helps us to identify which genes are involved, leading us to study their function in much greater detail,” he said.

The study may also help to understand why some people are more susceptible to early cognitive decline than others.

“We are interested in understanding individual differences between people in memory and learning because that may lead to a better understanding of why some people cognitively age better than others, and why some people are genetically more susceptible to dementia,” Professor Visscher said.

The study had a sample size about ten times larger than any other study investigating social-scientific outcomes.

“By increasing the number of individuals, we can move toward having a better understanding of the true effects of individual genetic markers on behavioural traits,” Professor Visscher said.

The study, “GWAS of 126,559 individuals identifies genetic variants associated with educational attainment”, was published in the 21 June issue of Science, 340:1467-71.