Sorry I have to disagree, it is human nature to make snap judgements based on someone's appearance part of our early survival instincts I'm sure, but we have evolved, well most of us anyway, and it is a small and insecure person that attempts to increase their stature social or emotional by belittling others.
You must have a narrow range of actual worldly experience, or be very young and sheltered. Do you dispute the racial and ethnic groups around the world, are often in conflict?
Kurds, to name just one. Or did you know the Swedes and Danes look down upon their Lapps, for another example.
Or that people from elite private schools, look down on lowly public school graduates? Or that muslims look down on and treat non-muslims differently and poorly?
Or that lawyers look down on mere ordinary people? Or that Catholics have been in conflict with Protestants in Northern Ireland, for a long time.
The US military was segregated during WWII. Filipinos could serve in our Navy, but only in certain jobs.
Or that Japanese feel superior to everybody else? Or that Northerners in America look down on Southerners, even today?
Or that city folks look down on rural folks, both in America and certain other places?
Or that various castes and strata exist in Brazil, India, South Africa, which rank the status/standing of racial and ethnic groups?
Ironically you were too quick to read everything that I wrote, since apparently you only wished to opine your social justice warrior white guilt trip on us.