Yep, Charles Murray wrote a whole book, of which one third deals with IQ and the genetics of intelligence in the context of class differences. It came out during Covid (called, ironically, "Human Diversity") and the major claims were basically: 1) races exist in a genetic sense, 2) classes exist due to intrinsic differences in intelligence, which has a genetic basis, and 3) gender differences are rooted in biology. (He actually had 10 claims in his book but they revolve around these three areas).
I developed a whole class to deal with these claims. But I agree, the right is obsessed with genes and IQ especially. What is emerging from the very latest research in behavior genetics is that the heritability of intelligence, which was once thought to be up around 50-60% (meaning, for a population of individuals that takes an IQ test--which is often used as a proxy for intelligence--50 to 60% of the differences in IQ scores can be attributed to differences in what genes individuals have inherited from mom/dad, where as 40-50% of the differences in IQ scores are due to things like differences in school, upbringing, etc.). Almost all these estimates of heritability are based on twin-studies. But newest research, based on genome-wide association studies (sample sizes in the millions) suggest the heritability of intelligence, and more generally the heritability of "educational attainment" (since IQ scores aren't available for everyone, but how much schooling they completed is) is like 10-20%, meaning, again, 10-20% of the differences in educational attainment (or IQ scores) can be attributed to differences in genes that people inherit, while 80-90% is attributed to the environment. Much more nurture than nature. And much much more than has been argued for decades.
[full disclosure, I'm not one to simply reject IQ tests outright, they have some usefulness and at present there isn't any other better way to measure what we define as intelligence. They are flawed, however, in their deployment, since things like stress, poverty, upbringing, schooling, etc., can distort one's performance on them, and certainly flawed in how much some sections of society place value on them. I'm not defending their use, just saying there isn't a widely-used alternative that I'm aware of].
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