The argument that "we're all one race" is practically worthless as far as explaining why some groups of people act different than other groups.
In his almost totally meretricious book "Guns, Germs, and Steel" Prof. Jared Diamond tried to prove that every group of people is as intelligent as every other group of people around the world. Nobody really believes that except ossified leftists and people who hate western civilization.
A better quest would be to find out why certain groups of the world's denizens have done far more than other groups in creating civilization as we know it. But then the issue of IQ would enter into the conversation. That's something leftists choose to ignore or seek to demolish. Except there it is.
When all the great thinkers in the world show people of sub-Saharan Africa or Australian aborigines with the same IQs as east Asians or Europeans, then I'll believe in the "we're all the same" theory.
Apparently attractive but having in reality no value or integrity.