Anticipating people to act out the persona they project is just a lack of stupidity. If they don't, you get to be pleasantly surprised. Theres not much downside to that.
You've never struck me as a person who would treat an individual differently, once you've spoken to them and identified them as 'good' or 'bad' by whatever lizard-brain thing calculates that shit.
I don't think racism is the perfect definition of what you, or I, or most people have. I think its a wary predisposition to avoid unacceptable cultural splatter.