A few people have inquired of the PNAS paper On sharing genes with friends. I avoided comment in part because I’m skeptical of the findings. So much behavior genomics just hasn’t panned out over the long term, and is probably susceptible to the issues which fuel the “decline effect”. Statistical significance is a random variable too. The fundamental issue which I want to emphasize is this: many behavioral traits are highly heritable, insofar as the correlation between relatives of trait value is in direct proportion to their genetic correlation. But, just because a trait is heritable does not mean that you can affix the variation to a specific set of genes. That is because the character of genetic architecture varies, and it may be that for many behavioral traits with some biological basis the causal variants which are responsible for the range in trait values are distributed across thousands of genes, and so are of very small effect.
Carl Zimmer relayed the depth of skepticism in the scientific community yesterday, and today Dr. Daniel MacArthur reviewed the paper. Here are the top line reactions:
Altshuler’s skeptical view of the paper was fairly widely shared by …