Why are women still considered to be minorities?

We are Yázigi Internexus students from Florianópolis. We are developing a research about the differences between men and women. Why do we keep this prejudice until nowadays? If you look back to the past, you will see that our society has always been prejudiced. Women have never had the right of an opinion! For instance, until the beginning of the XX Century women could not vote, since they weren't considered to be citizens! What's also disappointing about it is that such prejudice continues today. There are two kinds of prejudice, first a stronger prejudice like in Muslim religion, second a hidden prejudice as we have in Brazil. Since the world is getting bigger and technology is becoming more advanced, we wonder if such problem will continue to exist, or if our society will became really equal.

That's why we want your opinion about this topic. So, please, answer the following questions!