I think this topic is a bit overrated. Mankind itself is racist.
This topic is vastly overrated.
As the insightful BrutalButcher so eloquently articulates, mankind is indeed racist, which, in fact, is a subset of mankind's more notorious condition - tribalism. The conscientious reader will note the various categories into which mankind divides itself and the consequent behavior (choose the appropriate "-ism," there are many).
So mankind stratifies itself with respect to race, ethnicity, nationality, family, religion, favorite football team, political party, etc. Such is the way of homo sapiens sapiens
As King Solomon informed us, "nothing new under the sun