This isn't a "nerd" issue. And it is a fallacy to believe nerds should act better because we are nerds and live in a vacuum of only dealing with other nerds. The idea should be that we are the only ones acting this way (and no one else does), or that we are better than everyone else.
The negative behavior is actually TAUGHT, and taught early on. This is how everyone in the western world is taught to debate opinions. Look at any high school debate club, political debates, and any other televised debate. The behavior starts there. As a society, people are not taught to be civil when dealing with disagreements. There is just an inherent "You are completely with me and my friend, or we are enemies".
The negative behavior is actually TAUGHT, and taught early on. This is how everyone in the western world is taught to debate opinions. Look at any high school debate club, political debates, and any other televised debate. The behavior starts there. As a society, people are not taught to be civil when dealing with disagreements. There is just an inherent "You are completely with me and my friend, or we are enemies".