Because intelligence can be defined as the ability to adapt situations to your advantage, it’s only natural to expect smart populations to exploit less smart populations. In the extreme case this is known as slavery. For example, humans are smarter than animals and thus enslave horses, camels and other beasts of burden.
Thus if HBD is true, we should expect that among humans, high IQ races turn lower IQ races into beasts of burden, and indeed this has been a major theme of history. Caucasoids enslaved blacks, and among blacks, the Bantu enslaved the lower IQ pygmies. Meanwhile among Caucasoids, the high IQ Ashkenazim have arguably enslaved whites to the extent that they have tricked them into fighting Israel’s enemies for them in the Middle East.
There are exceptions though. Whites have higher IQs than Arabs yet Arabs enslaved whites. East Asians have higher IQs than whites, yet whites have never been enslaved by East Asians.
Aside from our enormous brains, it’s our ability to enslave other animals that most shows the supremacy of human intelligence. Thus among humans we should find that on average, big brained races are smarter than small brained races and that slave master races are smarter than slave races.
Of course some slave races are smarter than the very groups who enslaved them (i.e. whites vs their Arab slave masters ), and some smaller brained races are smarter than their bigger brained counterparts (high IQ Ashkenazim vs the big brained white race), however if my race not only enslaved your race, but ALSO has a bigger brain, I guarantee my race is smarter than yours AND that it’s genetic (on average of course).