> I wonder why we haven’t classified racism as a personality disorder, much like sociopathy or BPD. Viewing other human beings as lesser and having no sympathy for them seems to fit the bill.

Cynical answer: Because humans naturally like to punch down. Look at the comments that come up every time raising the min wage is discussed. "Ho-hum, I don't make $15/hr so these cashiers [who the commenters think are inferior] should live in cardboard shack if they don't like it" type comments.

Its hard for something to be labeled a disorder when most of the population seems to have it.