Genetic variation is key to problem-solving skills

Dr W. David Hill (Psychology, Centre for Cognitive Ageing and Cognitive Epidemiology) and colleagues at the Universities of Edinburgh, Göttingen, and the Max Planck Institute for Human Development in Germany, have published a study suggesting that more than half of the difference in intelligence between people can be traced back to their genes. The study used data from 'Generation Scotland' - a resource of human biological samples and data which are available for medical research.

The team  examined thousands of genetic markers in 20,000 people’s DNA to determine the genetic signals associated with their intelligence.  They used two statistical methods to work out how much effect rare genetic variants had on intelligence and  found that the combined effect of rare genetic variants and common genetic variants explained 50 per cent of difference in intelligence. The team also found that rare genetic variants accounted for a disproportionate amount of intelligence compared to more common genetic variants.

Previous molecular genetic studies have not been able to provide an estimate of the effect that rare genetic variants may have on intelligence, and so this study is the first to provide a measure of the influence that rare genetic variants have on intelligence.

Dr David Hill said: “We used two methods to measure the effect that rare variants had on intelligence. By combining the effect of both rare and common variants, more than 50 per cent of the differences in intelligence between people could be traced to their genes.”

The University of Edinburgh Centre for Cognitive Ageing and Cognitive Epidemiology receives funding from the Medical Research Council (MRC) and the Biotechnology and Biological Sciences Research Council.