How much of intelligence and personality is inherited?
June 2017: Research undertaken using Generation Scotland Biobank data was featured in the online Daily News article from the New Scientist.
Research undertaken using Generation Scotland Biobank data was featured in an online New Scientist Daily News article on 20 June 2017.
Genetic analysis of families in Scotland indicates that ‘more intelligent’ people have fewer DNA mutations that impair intelligence and general health, rather than having more genetic variants that increase intelligence. Intelligence depends partly on environmental factors but genes have an influence. Research on twins has suggested that 50-80% of the variation in general intelligence between people could be down to genes but the gene variants responsible for intelligence haven’t yet been identified. Studies of the DNA of hundreds of thousands of unrelated people suggest that only around 30% of the variation in intelligence is inherited. This differences between these percentages between the results of twin studies and genome studies has become known as the mystery of the missing heritability.
“This is one of the most exciting studies on the genetics of intelligence I’ve seen for a while,” says Steve Stewart-Williams of the University of Nottingham Malaysia Campus, who was not involved in the work.
One implication is that using gene editing to fix the hundreds of mutations that slightly damage people’s health would make them smarter as well as healthier. “I think this strengthens the moral case for pursuing genome editing technologies,” says ethicist Christopher Gyngell of the University of Oxford. “It would be killing two birds with one stone, and that would be a good thing.”
The research team analysed data from 20,000 people within the Generation Scotland biobank study, which is looking at the health and genomes of families. The research team used a statistical method to work out how much effect rare genetic variants shared by most of the members of a family have on intelligence. As these variants are so rare in unrelated people, other studies have missed their effect. They found that these rare genetic variants explain the differences in the percentage variation calculated by the twin studies and genome studies. “If the result stands up, they’ve solved the missing heritability problem for intelligence,” says Stewart-Williams. “Pretty impressive.”
“DNA variants that are bad for health may also make you stupid” New Scientist Daily News article published online (20.06.17)
Research paper “Genomic analysis of family data reveals additional genetic effects on intelligence and personality”, published online BioRxiv (06.02.17) doi:10.1101/106203.