The automatic characterization of examining human biodiversity as "Nazi race science" is a little concerning to me. While I understand that 95% of the people intrigued by HBD probably aren't in it for the sake of biology as much as they are for the sake of bigotry, I feel that Scott's treatment of it in that email was fairly reasonable. I certainly don't know enough about genetics, nature vs nurture, impacts of socioeconomics and culture, etc. to have an opinion on HBD, but I'm tentatively willing to acknowledge that there are probably at least two people groups in the world whose brains have adapted differently to different problem domains (though I'm strongly opposed to the idea that those two groups are "black people in the USA" and "white people in the USA"). If this wasn't true, it would be surprising enough to me that I'd need reasonable evidence to the contrary. If it is true, then it's likely significant, and needs to be talked about with the appropriate level of discourse. From his other writing, I feel like Scott understands this, and him limiting his statement on HBD to an email is due to the fact that it's incredibly hard to do so responsibly, and incredibly scary - e.g. my green account and the fact I fired up Tor to write this.