Good advice even now, isn't it? If only! Some of this reminds me of Covey's Seven Habits: seek first to understand, then to be understood, specifically. Again, if only!
Perhaps it boils down to a lack of respect for the other person. Perhaps we don't really believe the other person is worth respect, be it because of their social or economic standing, or maybe education level. Whatever the cause, they are still made in the image of God and worthy of respect. Jesus died for them as much as for you. Reread C.S. Lewis's essay "Weight of Glory" for a quick refresher course on what the image of God implies.