Whether you think a fact is "racist" has no bearing on whether it is true. Do you deny that there are measurable, meaningful genetic differences between groups of people? How can you justify the belief that adaptation to drastically different environments over thousands of generations after leaving Africa magically stopped above the shoulders?

What about geographically isolated interbreeding with other homonids? Those genes are also unevenly distributed; why would these genes not influence cognition?

One striking example is the so called warrior gene, which completely alters the metabolism of monoamines, like dopamine and serotonin, which have direct influences over reward seeking, mood, and behavior. This mutation is nearly absent in many populations. There are plenty of other such unevenly distributed variations.

Note that this does not imply that all people from group X are Y. But it does neatly explain, at least in part, multimodal statistical distributions like those we see consistently reflected IQ and crime frequency.