Gender Bias in Schools

Today Fernanda Cortés presented about Gender Bias. She was nervous at first, but then she stopped and calmed down. She gave a lot of examples of words that could sound malish to us and she gave us some alternatives to use instead of the malish words.
I believe that some teachers fall into the thing of the gender bias, when they prefer boys or girls in the class. This issue can be a little subtle, but is proved that, for example, some female teachers tend to prefer boys in their classes, but they don't even notice this, because their preference is marked in thei attittudes toward boys, treating them better than to girls.