I’ve noticed a tendency in myself and others during debate to only respond to the parts of what others say that I disagree with, taking the agreement for granted. This makes some sense; if you agree with 95% of an argument somebody is making, there is the most progress to be made by focusing on the 5% remaining difference. But I think this also causes the perception on both sides that there is a greater distance to be bridged than there is in reality. Constantly focusing on subtle points of disagreement can also be perceived as being unresponsive and indifferent towards a significant part of the arguments being made.
This is an optimistic take on phenomena like the backfire effect – a lot of the sense that you and your interlocutor are getting no closer during conversation might be the result of this form of miscommunication. I think a good policy for reducing misunderstanding is something like Rapaport’s rules – explicitly stating points of agreement before going into disagreement. This isn’t only good for reducing misunderstanding – I’ve noticed that stating points of agreement, especially things I’ve just been convinced of, has the effect of actually making it easier to change my mind.