Basically, east asians on average are smarter than europeans, who are smarter than africans. IQ tests consistently show these results, across multiple different kinds of tests (including tests deliberately trying as hard as they can to be non-cultural) and in different parts of the world. Other genetic things such as skull capacity and nearsightedness which have documented correlations with IQ also vary along the same lines between these groups, with the most incidence of myopia and highest cranial capacity in east asians, and lowest in africans.
In studies of adopted children (adopted into white middle class homes), children with 2 black biological parents have an average IQ which is lower than those with 1, which is lower than children with 2 white biological parents, despite being raised in good as opposed to a bad environment. Similarly, east asian adopted children have average IQs significantly higher than the average for their white parents. This doesn't really make sense if race genetics play no part in IQ.
If you look at regression to the mean (ie when two smart people have a dumber child, the child being closer to the average) the magnitude of the regression falls in line with the different racial average IQs. Children born to wealthy, high IQ black parents have IQ on average 2 to 4 points lower than those born to poor, low IQ white parents.