Steve Taylor (LeedsBeckettU) identifies five stages in becoming a racist:

a lack of security & identity prompts desire to affiliate with a group;

groups solidify themselves by identifying an 'other';

any empathy with the 'other' is denied;

all 'others' are lumped together & depersonalised;

the 'others' are then identified as scapegoats for failings that are driven by wider social processes.

Not sure this is anything really new but it's clear & plausible.

#racism
https://theconversation.com/racism-isnt-innate-here-are-five-psychological-stages-that-may-lead-to-it-264391