I disagree I think it is quite normal and natural although it is also true it can be learned. But take a look at all those double-blind experiments they did with the Aborigines kids that they took and brought over to Belgium and then took the Belgian kids and brought them over there to Papua New Guinea and that double blind experiment from 1967. that wasn't learned that was straight out first time ever experiencing it and the results were not surprising at all really. the kids had a strong aversion to the kids who did not look anything like them at all. It is quite natural indeed