Handwaving.
Literally the only reason the topic of "statistical differences in IQ across the population" comes up on this site is as a defense for why there's a microscopic population of African Americans and Latinos in our industry. The reason, the logic goes, is that the supposed racial IQ differences mean that there simply aren't enough African Americans intellectually qualified for the field.
There are plenty of reasons why a cohort of US persons of African descent could have lower recorded IQ scores than US persons of European descent. I'm not the one making the logical leap that the reason is a genetic disposition towards lower intelligence, rather than socioeconomic, environmental, or methodological issues. The white supremacists are the ones saying that†. If you're not, and you're not bringing the topic up unbidden as a defense of the status quo, I'm not saying anything about you.
I'm not interested in pretending that there's a good or rational kind of white supremacist. Several people on this site, and this thread, seem determined to do so. You can, too, and I won't stop you, but "good kind" or "bad kind" I'm going to call them what they are.
† (much to the consternation of some of the best-known people doing the actual science)