It doesn't sound normal to me. To me we are all in one big gang. Think about it. No one can control others. We can only control ourselves.
People are afraid of the unknown.
Maybe even teachers are part of the problem. I feel this is a problem. If a person has less money than others, he won't be accepted. No one can be rich, athletic, and smart at the same time. And if you can't accept that, well, you have a problem.