[homogeneous]

I hope I have not misinterpreted your position.

> We're almost certainly going to discover less palatable differences between races -- e.g. around intelligence.

I read that as "we are almost certainly going to discover, for example, that some races are more intelligent than other races". From this statement it follows that we will be able to prove that some races are "more intelligent" and some races are "less intelligent", thus it seems fair to conclude that you're asserting that the genetic factors that cause someone to fall into a specific racial category predisposes them to a certain level of intelligence. From that position we can conclude that if an individual displays the phenotypic traits that meet the definition of one of the less intelligent races, it follows that this individual would be genetically predisposed to less intelligence, also known as stupidity.

I do notice that you said "almost certainly", not "inevitably" so I apologize for that, but please let me know if I have otherwise misinterpreted your position.