[Ditto]

Do you have any empirical reason to reject the hypothesis that there are genetic differences between races and ethnicities?

No. Just 60 years of experience. I have known a lot of stupid people and a lot of very bright people and a lot more of people in the middle. It seems to me that the culture those people were raised in made the difference not some genetic factor related to an arbitrary definition of intelligence.

And other than measuring the extremes on either end, IQ tests, IMHO, are absolutely meaningless. Success and accomplishment is far more based on a persons willingness to succeed it what ever endeavor they choose.

[curiosity]

No. Just 60 years of experience. I have known a lot of stupid people and a lot of very bright people and a lot more of people in the middle.

Drawing inferences from anecdotal evidence, especially personal anecdotal evidence, is generally a bad idea.