Actually that does not require very much extrapolation. Racism seems to be in their DNA. Much more so than in Caucasians.
Something else that also gets overlooked is that warring tribes in Africa sold slaves to the traders. That is how the slave trade started. In some places, this is still going on, or so I’ve read.
I disagree. It's not a DNA thing and you'll find it in all races in different times and places. Not every individual of course, but it's common across the centuries, the continents and the cultures.
It's something we more or less have in common.