We start by accusing the other, either verbally or silently, of that which we perceive as a wrong-doing, using that wrong-doing as an excuse to justify as reasonable and acceptable our (certainly not virtuous) act of distrustful accusation.
Because we wish to maintain our perception of ourselves as in the right, we try to hide or deny our dismissive, judgmental attitudes towards those we accuse, playing polite and trying to behave outwardly in a civilized manner, but we cannot fool those we've accused. Our attitude and feelings towards them are definitely clear to them.
Feeling obviously accused and judged, even though we may have never verbalized our accusations, they take a defensive stance, and, in turn, either silently or verbally accuse us as the ones perpetrating offence and antagonism, seeing themselves as innocent, wrapping their responses in polite phrases while seething inside, denying in turn the error of their own accusatory feelings and responses to us.
We in turn perceive their response to us and feel just as offended by it as they were by ours. In our minds their defensiveness and accusations give us "proof" that we are acting on the higher moral ground and that we are justified in judging and accusing them of failure to do what is right.
Because we are so absorbed in our own feelings about the conflict and our feelings in response to their accusations we do not see what is going on. We do not see that instead of trying to hurt us they feel mistreated and intentionally disregarded. We do not see that in their response to us they are trying to deal with the judgmental person we have become; that they are only responding to the kind of person we've given them to respond to.
In sum: We concentrate on what we perceive as their misdeeds in order to find proof and reassure ourselves that they are to blame, that they are the reason we're in this conflict, not us. And they focus on our misdeeds to for the same reason. And round and round it goes, tying us tightly to our responses to each other into an endless, edgy conflict in which each blames the other and exonerates self.
It is the antithesis of dialogue and comprehension, masquerading as civilized discourse.
Adapted from C. Terry Warner's book "The Bonds that Make Us Free".