GWAS studies are rapidly establishing the role that common gene variants play in individual variation in complex traits. Height, educational attainment, IQ, various health risks. They can also be used to investigate average trait differences between groups. There are technical complications in doing that – GWAS might have found a SNP that is only linked to the causal SNP, and that linkage may be different in another, fairly distant population. A very [genetically] distant population might have a significant number of entirely different variants influencing the trait. In other words, Bushmen may be so genetically different on some trait that you can’t use a GWAS score to show that they’re different. So different that they might be the same.
But I’ll bet that the great majority of the time, people that look short – especially if they look short in a wide range of environments – actually are genetically inclined to be short. I think we will find that populations that show high intellectual performance in a wide range of environments actually are genetically inclined to be smart, and those that show low performance in a wide range of environments mostly won’t be.
What you see is what you get. David Reich may say that nobody knows, but it’s the way to bet.