I'm going to treat a student differently from other people.
Why would you treat them differently?
It's because I think the student's lower than me.
Well, I think treating somebody differently simply because they are a student is wrong and rude. You should get to know them first, and figure out if you like them. Otherwise it is just rushing to judgement.
I don't have time for that.
I don't know why you would see someone as beneath you just because they are a student, that seems arrogant. You should treat this student with as much respect as you would anyone else.