It is strange, but do you know that you are most likely unaware of the world outside your comfort zone? I grew up in a white straight neighborhood. When a Korean family moved in it seemed like a big uproar, and when a black family moved in, that was the end of the neighborhood as we knew it according to people back then. It isn’t that people in the neighborhood were racist persay, but they lived in a white neighborhood, and when people who looked different moved in, they were moving into an already established comfort zone of people. People don’t just do it with race though.
A few years ago, unless a guy acted feminine, or or a woman was very butch looking, I would assume that they were straight. My cousin is a butch kind of lesbian, so maybe that is where I different and think that way, but now I live in a primarily gay town so it is harder to tell than just the black and white perceptions of people.
We do this, not with people, but with fictional characters as well. Being white, I was brought up to believe that Santa Clause was also Caucasian. But if you are black, maybe you had an African American Santa Clause. Even the differences between the sexes is apparent. How many times do women refer to god as she, while men refer to god as him?
Take a step outside your comfort zone, look around at the world, take a drive through harlem, see how the other half live. You might be surprised with yourself.