system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How did societies that mistreated slaves get into a mindset where their slaves were inferior/not humans?

I am just wondering how it could have spread and who started it.
gpt
Suppose you're Jose Conquistador, and you've just arrived in what is now Mexico. You meet natives, who seem totally unaware of even the basics of civilized culture - their women go about with breasts uncovered, they cannot understand any known language, they even lack knowledge of the one true God! Truly, they must be a terribly primitive people.

It's easy to interpret "different culture" as "worse culture", basically. It probably didn't help that, because of superior military technology, Europeans had little trouble kicking pretty much everybody elses' asses during the colonial era - when a hundred of your guys can beat ten thousand of theirs, it's hard not to feel superior *as people* and not just in tech (even if the fight was far from fair to begin with).