Immaturity is what I will call it. If not why will siblings that are supporting different clubs fight over a football match, when they don't have anything to benefit. It is a shame that we take things that are not so important as if they are more important than our family bond. When I see those football fans arguing and quarreling, I feel bad because it does not worth it. You can be a fan of your favorite club but not an arrogant one. Only I and my younger brother that are football freaks but we are we are fans of one club.
This is about fanaticism, there is a reason some sports are thought of as an unofficial religion in some countries, and the one that causes this reaction way more often is socces, so if a person supports a team different than the one you support, for the person that is a total fanatic and believes on their team with a fervor often reserved by other people for their religious beliefs, then they will think of you as their enemy, to the point a fist fight may occur.
