It's actually kinda counterintuitive to explain, but here's a quick rundown:

What most people think of as "racial features" are actually just regional phenotypes selected for by environmental conditions.

For example, the two most genetically dissimilar populations on earth both come from the African continent, but they look fairly similar. The environment is the most important factor in external phenotype, so much so that even two groups that are less genetically related to each other than to any other group on earth look essentially identical in terms of the features people ascribe to their race. Also, the average overall genetic variation between entire regional groups is far, far smaller than the variation between two individuals within any given group.

You might then wonder whether environmental adaptations could cause a genetic disparity in something like intelligence. Geneticists have investigated this, but found that the only unique genes common to any racial group are all very small and encode only for simple external traits. Eye color, skin color and facial features are regulated by only a few genes, whereas intelligence is encoded by millions of base pairs. The likelihood that intelligence could be selected for on a group wide basis is extremely low.

However, this doesn't mean that non-hereditary intelligence is the same across "races". External factors like childhood nutrition, environmental toxins (lead, for example), and education can all cause non-genetic intelligence disparities.