A reader writes:
The new paper by Piffer (PDF downloadable here), or at least the first part, is fairly memorable. Correlations between national average IQs and the top seven alleles aren’t bad. Piffer and his partner are able to show that other alleles that track with the known IQ alleles across populations are overrepresented in Craig Venter and James D. Watson (who are smart guys, I presume), who have had their genomes published. …
The research will get stronger if they use the other approximately 60 alleles listed in the recent study. It would be even better if they used all of the numbers about the millions of SNPs from that large study by Rietveld et al. Nonetheless, it’s really getting pretty obvious that there are sizable genetic population differences more or less following the phenotypes, although lots of details remain to be scoped out more clearly.
Here’s the abstract:
Comparison of allele frequency patterns across many loci has recently been used to identify selective pressure on polygenic traits such as height and IQ. In this paper, we used one such approach based on principal components analysis, and analyzed GWAS hits from recent studies whose effect on intelligence has been replicated. The component scores had very strong correlations with estimates of country/population IQ (r around 0.8-0.9). To further validate this approach, we tested the prediction that the alleles positively correlated to the principal component (PC) are overrepresented among highly intelligent individuals. James Watson and Craig Venter both meet this requirement and have their genomes freely available online. We found an overrepresentation (compared to the 1000 Genomes CEU sample) of alleles correlated with our PC in Watson and Venter’s genomes, suggesting that our PCs could represent a genuine signal of selection pressure on intelligence across many genes. We found that among the alleles correlated with our PCs, there is a higher ratio of derived:ancestral alleles compared to SNPs uncorrelated to the PC. This is in accord with the increase of human intelligence during hominin evolution.