[2] above already shows there is no scientific basis to genetics explaining intelligence variations in human groups. Other studies [3] back this up, and there are studies clearly tying intelligence variations between human groups to environmental factors [4] [5].
Based on the easily googled wide availability of this information and given the environmental causes of IQ differences, I wonder if an easy scientific corollary is that racists must have environmental factors behind their inability to comprehend the established science in this matter. LoL
[3] https://doi.org/10.1073/pnas.2322874121