“But two commentators suggest that there are basic biological explanations for this anger as well. Michael Bradley and Frances Cress-Welsing contend that white people are unconsciously motivated to annihilate others because they fear that their genes will be overwhelmed by the dominant traits of people of color, that white supremacy is actually a defensive posture.”

I’m skeptical about this. I’ve read about studies that the brain of a baby more easily recognizes faces of it’s own corresponding race as a possible explanation for racial tribalism, but that was for all races (European, African, East Asian, etc). I’ve never seen a study that comes close to suggesting a biological basis of racial animosity especially unique to Europeans. In the real world I’ve seen racial tribalism coming from all corners of the world, so I think tribalism is hardwired into our brains (and is an urge we must resist!). But specific to white people? I would need more proof.