Effective altruism is based on the core belief that all people count equally. We unequivocally condemn Nick Bostrom’s recklessly flawed and reprehensible words. We reject this unacceptable racist language, and the callous discussion of ideas that can and have harmed Black people. It is fundamentally inconsistent with our mission of building an inclusive and welcoming community.
— The Centre for Effective Altruism
I downvoted it (weakly) because my impression is that "it's pseudoscience" is not a nuanced statement on a topic where there's bad science all over the place on both sides. Apart from the awfully racially-biased beliefs of many early scientists/geneticists, there has been a lot of pseudoscience from far right sources on this also more recently – that's important to mention – but so has there been pseudoscience in Soviet Russia (Lysenkoism) that goes in the other ideological direction and we're currently undergoing a wave of science denial where it's controversial in some circles to believe that there are any psychological differences whatsoever between men and women. Inheritance stuff also seems notoriously difficult to pin down because there's a sense in which everything is "partly environmental" (if put babies on the moon, they all end up dead) and you cannot learn much from simple correlation studies (there could still be environmental influences in there). I think a lot of the argument against genetic influences is about pointing out these limitations of the research and then concluding that, because of the limitations, it must be environmental only. But that's only half-right: if the research has all these limitations, it makes more sense to be uncertain about the causes.
When I closely followed the controversy around Sam Harris and his interview of Charles Murray and later the conflict and subsequent discussion between Sam Harris and Ezra Klein, I noticed that the side that was accusing Sam Harris of pandering to pseudoscience was lying about a bunch of easily-verifiable things. I'm not sure I would understand the science well enough to say that they're wrong about their scientific claims (and I didn't bother to read their work in detail), but I think it's good practice not to trust liars. (Ezra Klein was more of a weasel in that discussion than a liar – the people I think were lying were people whose hit piece against Harris and Murray Ezra Klein allowed to be published on Vox.)
Given the above, it seems possible to me that genetic influences also play a role. It seems plausible on priors (would be a coincidence if all groups are the same in all regards), we have some precedent for group differences (I think the research on Ashkenazi jews having higher average IQ is less controversial?), and it can't fill you with confidence in the other position when we can observe how some people are morally confused so they think the topic is so politically dangerous that they feel the need to lie about things (e.g., in the Sam Harris context, but also recent EA twitter threads I've seen go in that direction).
It seems clear that some group differences are environmental-only. However, note that, even if they weren't, it wouldn't have any political implications. The benefits of access to good things that underprivileged groups often have less of, like access to education, health care, infrastructure, both parents involved in upbringing (though of course many single parents do an excellent job raising their kids), etc., these benefits don't have much to do with IQ increases! Instead, access to these things is beneficial in all kinds of ways for anyone. So, politically, nothing would change and it would remain morally important to work towards more equality.
As I said before, it's totally counterproductive for the goal of fighting racism to stake your case on scientific claims that could turn out to be false. (Imagine how much of a convenient weapon you'd be handing over to racists if they can point out how the anti-racists are staking their claims on potentially flawed science and how they're punishing anyone who expresses uncertainty.) There's no reason to consider group averages morally relevant. It's a huge confusion to act as though there's a lot that morally depends on it.
I also downvoted sapphire's comments in some places (though not this thread) because they make it seem like there's some conspiracy in EA around this stuff and because I don't like their use of the term "Scientific Racism." (I think the term is very appropriate for many scientists in the early 20th century or before, but very unfair to use towards people like Charles Murray or ones who say things like Bostrom said in his apology.) Regarding the alleged conspiracy, I had to look up what "HBD" exactly means. It might be true that some contrarian types are drawn to these topics in Bay area and via that spinoff from Slatestarcodex where people get kicks from discussing controversial topics. But that seems not particularly representative to me (and more rationalists than EAs)? In any case, I mostly talk to EAs in London and Oxford, where I've never seen anyone express any interest in these topics whatsoever, "EA leadership" least of all. I agree that the voting patterns maybe suggests something about EA being unusual, but to me that mostly implies stuff like "EAs/rationalists are skeptical of making confident claims where the evidence is unlikely to support such claims."