[...Hmm, right. Well, while Dash can't think of an exact situation like that, prejudice does kinda ring familiar to her.]

Well, we don't have anything that serious back home, but we used to all freak out whenever this Zebra named Zecora dropped by Ponyville. We thought she was evil and that she'd put all kinds of creepy curses on us.

I think sometimes fear can really twist the way you look at somebody, especially if they're strange, different, or stronger than you. If people are treating 'em like monsters, maybe it's because they feel threatened.