Robert Black said this quote

Human beings are very skilled at pretending they are not what they are, and ignoring what is inside them. This includes ignoring their natural instincts, their primal instincts, because they have this notion that they are evolving faster than other life, have evolved further, and are therefore superior. Take racism for example. As abhorrent as people may consider it, human beings are essentially tribal, and racism is simply a survival instinct embedded deep inside us, born from thousands of years of survival and experience.