I suspect a surprising percentage of people just follow the crowd. No effort required to formulate any bigotry or predudice or whatever, just copy others and you're part of the gang. If there's nothing to copy they just shrink out of view.

If one stops drinking alcohol, one stops being drunk.

I think people in groups acclimatize to the vibe of their surroundings and verbalize things in a nudged way to land well within the group. So if the group is toxic, the nudge will be toxic.

Seem the same studies. Google "if you cut off access to Fox News and Facebook, people get less racist and wanting to do harm"

There are plenty of reputable resources to investigate.