In the days of slavery here in the USA, in order to justify the keeping of African people in bondage , like we did and still do,farm animals , they taught their children that Africans were not human. We even stipulated in our constitution that they are 3\5 human.
Then , the KKK used the same technique to justify their own belief that whites are superior. And to justify their behaviour concerning African Americans .
So many people grew up being taught and believing that African Americans are not human.its ingrained in their family structure. And part of their familial identification.
It is a crime against humanity when this occurs . And it will be many generations before it dies , but it will one day.