— Discrimination against a group can happen for different reasons: (i) the discriminating people feeling insecure and with a need to put down some other group. This seems to be inherent in humans. There's a consistent ingroup vs outgroup dynamic everywhere on lots of different axes. (ii) the avenging of a perceived slight by that group against the now discriminating group (iii) outright bullying for a perceived weakness.

— Some discrimination against black currently seems to exist because black people are thought of as undesirable: poor, uncultured and stupid. Discrimination on race doesn't occur against blacks alone. It does again other races too: Indians (all of the subcontinent), West Asians and North Africans (Arabs, Bedouins etc), Latinos, east Asians (Koreans, Chinese, Japanese etc) etc. But black people seem to bear the worst of it, and western Caucasians, the least. So maybe there is an order of races in order of increasing amounts of melanin... from western whites to African blacks? But why?

Is it based on economic and cultural success in the modern world.. around and after the beginning of industrialization? Or economic and cultural success before then? Granted that interaction between people from different places used to be rare and difficult, was there ever a time when black people were thought of more highly, and western caucasians were not at the top of the pyramid? Say in the 1300s? What civilizations were the most economically productive then, and what did each race think of one another?

Black Africa clearly is the most economically underdeveloped part of the world. There's been lots of explanations proposed for this: some of them are geographical, others are genetic (they claim black people are just outright stupid). So maybe this is why racism against blacks is the worst of all of them? What if black Africa became as developed as western Europe? Might there exist anyway this sort of discrimination against black people? Is it about the color of our skin, instead?