From Alexander P. Burgoyne and David Z. Hambrick at Scientific American:
In a GWAS recently published in Nature Genetics, a team of scientists from around the world analyzed the DNA sequences of 78,308 people for correlations with general intelligence, as measured by IQ tests.
Of the over 12 million SNPs analyzed, 336 correlated significantly with intelligence, implicating 22 different genes. One of the genes is involved in regulating the growth of neurons; another is associated with intellectual disability and cerebral malformation. Together, the SNPs accounted for about 5% of the differences across people in intelligence—a nearly two-fold increase over the last GWAS on intelligence. Examining larger patterns of SNPs, the researchers discovered an additional 30 genes related to intelligence.
Of course, intelligence is not solely the product of DNA—and no scientist studying intelligence thinks otherwise. The environment has a major impact on the development of intelligence, or any other psychological trait. More.
Given the disclaimer “intelligence is not solely the product of DNA,” one wonders: If a human being appears to have all his marbles but lacks four of those genes, is he still considered “intelligent”? Isn’t this one of those situations where what happens in real life is what fundamentally matters?
See also: Claims about flawed science and ape intelligence