This is a post written by David Thorstad, a philosophy professor who maintains a blog for criticizing various tenets of effective altruism called Reflective Altruism, as part of a series of on human biodiversity (HBD), a modern iteration of so-called race science. HBD, of course, isn't typical fare for EA, or any of its championed causes. Yet it has, to much controversy over the years, been recognized as a subject of interest among prominent thinkers associated with either the effective altruism or rationality communities, or others writers they've been affiliated with. This latest post in Thorstad's series provides a critical overview of @Scott Alexander's history of engagement with said body of ideas, both on his current blog, Astral Codex Ten (ACX), as well as before then, such as on his previous blog, Slate Star Codex (SSC).
The author spends no time discussing the object level, he just points at examples where Scott says things which are outside the Overton window, but he doesn't give factual counterarguments where what Scott says is supposed to be false.