I take this excerpt from Charles Murray, the most prominent social scientist on IQ, as instructive about the question of the importance of genetics. From an AEI interview:
On this score, the roof is about to crash in on those who insist on a purely environmental explanation of all sorts of ethnic differences, not just intelligence. Since the decoding of the genome, it has been securely established that race is not a social construct, evolution continued long after humans left Africa along different paths in different parts of the world, and recent evolution involves cognitive as well as physiological functioning.
The best summary of the evidence is found in the early chapters of Nicholas Wade’s recent book, “A Troublesome Inheritance.” We’re not talking about another 20 years before the purely environmental position is discredited, but probably less than a decade. What happens when a linchpin of political correctness becomes scientifically untenable? It should be interesting to watch. I confess to a problem with schadenfreude.
Murray summarizes Wade:
A 2009 appraisal of the available genome-wide scans estimated that 14% of the genome has been under the pressure of natural selection during the past 30,000 years, long after humans left Africa. The genes under selection include a wide variety of biological traits affecting everything from bone structure and diet to aspects of the brain and nervous system involving cognition and sensory perception.
The question, then, is whether the sets of genes under selection have varied across races, to which the answer is a clear yes. To date, studies of Caucasians, Asians and sub-Saharan Africans have found that of the hundreds of genetic regions under selection, about 75% to 80% are under selection in only one race.
It's fairly clear that human evolution didn't stop when humans left Africa--always a dubious claim. This claim's cousin, that genetic deviations are too small to matter or don't cluster around racial groups, has now been evaluated and found to be to be wanting.
Wade states definitely, same source:
“What these genes do within the brain is largely unknown,” Mr. Wade writes. “But the findings establish the obvious truth that brain genes do not lie in some special category exempt from natural selection. They are as much under evolutionary pressure as any other category of gene.”