Again, you're drawing very explicit conclusions from a few sentences. Racial disparities in IQ are indeed observed, but it's highly contentious over whether these are due to environmental factors like education and nutrition or inherent. That Asians have score higher IQs on average than whites in the US is an empirical observation. But it's also known that IQ can be increased by studying, and Asians study about twice as much as white people in childhood [1].

Scott is acknowledging that the taboo to even recognize these disparities is counterproductive: it stymied attempts to improve schooling or studying practices, because it's taboo to even recognize that there is a difference and instead people typically allege that the tests are biased. Would Scott argue that with identical environmental factors we'd still see the same disparities in IQ across ethnic groups? I don't think so, and nothing in the emails linked seem to suggest this.

1. https://www.brookings.edu/articles/analyzing-the-homework-ga...