For years I’ve seen speculation on HBD blogs (usually in the comment section), that a lot of HBD people are a little autistic. I believe this speculation is correct, but nobody to my knowledge has articulated why, probably because it’s so obvious; but here’s my explanation:
Autism is a phenotype defined by low social IQ and obsessive interests (especially mathematical ones). People with low social IQ are more likely to explore HBD because they don’t understand how politically incorrect certain parts of it are. In addition, autistics tend to treat other people like objects, or like animals, and HBD requires you to study human populations like they’re rats in a field, rather then thinking of humans as divine creature’s created in God’s image, and thus divorced from the laws of nature. In many ways autism is the opposite of schizophrenia, and since hyper-mentalizing schizophrenics tend to be very much in-touch with God, and other imaginary members of the spirit world, autistics tend to be very atheistic, and thus, huge believers in Darwin (to the point that they hyper-apply his theories to humans).
In addition, HBD requires a lot of math and statistics, so having an autistic obsession with numbers is very helpful.
Of course, not all (or even most) HBD people are autistic, but because many of them are, it becomes a vicious circle: Autistics are drawn to HBD because they don’t fully grasp it’s taboo nature, but HBD remains extremely taboo because the autistic HBD folks lack the social IQ to know how to market it.