An interesting essay on philosophical aggression by Norman Swartz (hat-tip: The Maverick Philosopher). Fortunately, I haven't seen very many of these incidents, although I've heard the stories; although I haven't ever seen any interactions along the lines that Swartz saw at GE, either. I'll have to work on bringing my own practice more in-line with that. In general I'm a sweetheart, and my first instinct on challenge is to back down, even when I'm sure I'm right. But I do tend to be less patient with people who think Aquinas, or Hume, or Descartes can be dismissed with a brief comment and a wave of the hand. Then my instinct is to 'go for the jugular'. I'm not sure why that is, unless it's the fact of dismissal itself.
I think for most people the aggression is actually just what you'd think - arrogance, either the frustrated arrogance of someone who wants to appear brilliant or the dogmatic arrogance of someone who thinks a different perspective than his own is merely intellectual perversity. Sometimes, I think, it's just argument-blinders - people getting too caught up in the argument (I've been guilty of that once or twice).
But I think the biggest problem is that we falsely tend to think that the primary unit of philosophy (so to speak) is the argument (in the logical sense) rather than the strategy or approach. In this I agree very much with the point of footnote # 3 in Swartz's essay.
A Further Thought (Added Later): I wonder if bloodsport syndrome comes about in part because of the nature of the discipline itself. People tend to want to trounce people who tread on their own discipline without adequate knowledge; perhaps the problem is that philosophy is so large and so interconnected that we are all intruding on each other's discipline, and tend all to regard each other like specialists might regard intruders from another discipline, rather than like colleagues from the same discipline. I don't know; it still wouldn't excuse it.