"A study from Iceland is the latest to raise the prospect of a downwards spiral into imbecility. The research from deCODE, a genetics firm in Reykjavik, finds that groups of genes that predispose people to spend more years in education became a little rarer in the country from 1910 to 1975.
The scientists used a database of more than 100,000 Icelanders to see how dozens of gene variants that affect educational attainment appeared in the population over time. They found a shallow decline over the 65 year period, implying a downturn in the natural inclination to rack up [academic] qualifications.
But the genes involved in education affected fertility too. Those who carried more “education genes” tended to have fewer children than others. This led the scientists to propose that the genes had become rarer in the population because, for all their qualifications, better educated people had contributed less than others to the Icelandic gene pool.
Spending longer in education and the career opportunities that provides is not the sole reason that better educated people tend to start families later and have fewer children, the study suggests. Many people who carried lots of genes for prolonged education left the system early and yet still had fewer children that the others. “It isn’t the case that education, or the career opportunities it provides, prevents you from having more children,” said Kari Stefansson, who led the study. “If you are genetically predisposed to have a lot of education, you are also predisposed to have fewer children.”
Robert Plomin, a behavioural geneticist at King’s College London said that the paper was a demonstration of how polygenic scores – which measure a person’s genetic strengths and weaknesses – are at the frontline of the DNA revolution. “They have already changed science and will soon affect the clinic and society,” he said.
“Although the effect of the polygenic score for educational attainment on fertility is weak and needs replication in populations other than Iceland, this study is a harbinger for the new directions in research that will be possible as bigger and better polygenic scores come online,” Plomin added."