Genetic variants that influences intellectual ability each make very small contributions. One reason for this is that the brain is very complex. To boost performance by a large amount it is not enough to tweak just one gene. Many different genes must be tweaked. This makes the job of finding genetic variants for IQ differences much harder to find. But the cost of genetic testing has gotten low enough that the search for IQ genes is starting to turn up useful results. Here's another report, this time from the Social Science Genetic Association Consortium (SSGAC): A few genetic variants that are associated with differences in educational attainment have been found by genetically testing about 125,000 people.
A multi-national team of researchers has identified genetic markers that predict educational attainment by pooling data from more than 125,000 individuals in the United States, Australia, and 13 western European countries.
The study, which appears in the journal Science, was conducted by the Social Science Genetic Association Consortium (SSGAC), which includes researchers at NYU, Erasmus University, Cornell University, Harvard University, the University of Bristol, and the University of Queensland, among other institutions.
The SSGAC conducted what is called a genome-wide association study (GWAS) to explore the link between genetic variation and educational attainment—the number of years of schooling completed by an individual and whether he or she graduated college. In a GWAS, researchers test hundreds of thousands of genetic markers for association with some characteristics such as a disease, trait or life outcome.
I am impressed that that the SSGAC exists. Social scientists looking for genetic evidence. It says something about the difficulty of the search that 125,000 people were needed to find genetic markers associated with a pretty small portion of the differences in educational attainment. Much larger data sets are needed.
A key claim from the abstract: "Three independent SNPs are genome-wide significant (rs9320913, rs11584700, rs4851266), and all three replicate."
Combining the 2 million examined SNPs, the SSGAC researchers were able to explain about 2 percent of the variation in educational attainment across individuals, and they anticipate that this figure will rise as larger samples become available.
We need larger data sets, perhaps a few million people. Plus, we need more genetic variants to test, including much lower frequency genetic variants.
|Share |||Randall Parker, 2013 May 30 10:44 PM|