least most

so this is realy my first "serious" post i guess, so here is my question; why is it that as soon as someone walks into a rrom everyone automaticly judges them on their appearance? for example, when you see a kid like brandon you assume he's emo, or when you see chenoa you assume she is a ho (even though she is thats besides the point), i th9nk that first judgements are wrong, and i would like everyone to reply to this. thx