MORE than 500 genes linked to intelligence have been identified in the largest study of its kind, involving almost a quarter of a million people from around the world.

Scientists from Edinburgh, Southampton and Harvard universities compared DNA variation in more than 240,000 people to determine which genes are associated with intelligence. They found 538 that played some role in intellectual ability.

They also found 187 regions in the human genome that are linked to thinking skills.

Researchers say the study sheds new light on the biological building blocks of people’s differences in intelligence.

They said genes found to be to intelligence also appeared to influence other biological processes, and some linked to intellectual ability were also associated with living longer.

Research teams found that genes linked with problem-solving powers were associated with the process by which neurons carry signals from one place to another in the brain. Using these discoveries, scientists next predicted intelligence differences in an independent group of individuals using their DNA alone.

Dr David Hill, from the University of Edinburgh’s Centre for Cognitive Ageing and Cognitive Epidemiology (CCACE), who led the research, said: “Our study identified a large number of genes linked to intelligence.

“Importantly, we were also able to identify some of the biological processes that genetic variation appears to influence to produce such differences in intelligence, and we were also able to predict intelligence in another group using only their DNA.”

The study’s principal investigator, Professor Ian Deary, also from the CCACE, said: “We know environments and genes both contribute to the differences we observe in people’s intelligence. This study adds to what we know about which genes influence intelligence and suggests that health and intelligence are related in part because some of the same genes influence them.”

The study, which used data from the UK Biobank, is published in the journal Molecular Psychiatry.