Opinion : Typical topics

When we talk about topics, basically we're referring to a typical "way of doing" of a collective. There are a lot of topics: they can talk about a country, of how to behave,... But, they are real, or is it just an invention? Those "ways of doing" have to had any reason, I think. Let's see some topics:

- Catalan people are stingy
- Girls are more emotional than boys *
- Boys don't cry in public and don't show their feelings *

I disagree with this, because I think that every person is a different world; maybe the topics could describe the "common" behaviour of people, but it was in the past. Now it have no sense. I think they're not real, because I have a lot of friends that behave contrary to the topics: for example, I know a boy who is the most emotional person I ever know.
These topics only contribute to make this society an intolerant one with all the person who have a different behaviour. I think that is better to make them disapear, because we can hurt someone with a topic.

* = In this society, we unconsciously assimilate that things; but now, more and more people behave in different forms, although a lot of people thinks that's "the correct way of behave". Obviously, I completely disagree with this "correct way of behave".

NOTE: I'm thinking in a photo!
NOTE 2: This is just my opinion. I apologize if I offended someone.