And likewise, not a single group or race on the planet has not oppressed/killed/tortured another group. We are all descended from victims and killers. In fact, it's much more likely that we are descended from killers, that's why we're here, and somebody else's descendants are not. Guns, Germs and Steel by Jared Diamond has a couple of interesting chapters on how the Bantu people of Africa wiped out dozens, maybe hundreds of other African tribes, and became the predominant people on the continent. Virtually all African-Americans are descended from Bantu people.
There is a fascinating book I have recommended dozens of times. “The 48 laws of power” by Robert Greene. It should sit on the bedstand of every person that even thinks they might really be a conservative.
It explains so much and so well about power, what it his and how the most powerful people in history have wielded it. For good and evil.
But this and your tribal example really come back to that whole education thing. People have been programmed to believe it’s not ‘cool’ to know things.
“Why” that is, is covered in the 48LP ;)
Then again, judging by your OP, I’ll bet you’ve read it.