Our brains are still evolving. The linked to article refers to recent genes found that regulate brain size. One gene rose around the time religion and agriculture appeared - very recently. Brain size is correlated with intelligence (with some exceptions), so these genes might explain ethnic differences in average intelligence.. But the bigger story is that we are all becoming smarter.
The ironic twist here is much of the human species might’ve became smarter to outmaneuver, outwit and kill foes. Our intelligence may bring us beyond the ancient fallacies that gave rise to it in the first place such as tribal hatred and racism. Nah, wishful thinking.