When I have something to say, that thought becomes the center of my attention, making it extremely hard for me to really listen to what someone else is saying.  Really listening requires that I make the other person’s ideas the center of my attention – that is the only way I have a chance of making the best part of his knowledge become part of my own mental map of the universe.  My own idea is already in my head, so I can come back to it later – though writing a quick note to myself may make it easier to recall when my turn does come around.

When are we most likely to be waiting for our turn to talk instead of listening?  Probably, it’s when we disagree with the other person. In that case the other person probably isn’t really listening to you either.  So in addition to not hearing each other’s ideas, the people start feeling frustrated that they are not getting listened to, and so the disagreement escalates into a heated argument.