…is to assume that they are uninformed, and that once they know what you know, they will change their mind. (A marketing problem!)
The second easiest way to disagree is to assume that the other person is a dolt, a loon, a misguided zealot who refuses to see the truth. Their selfish desire to win interferes with their understanding of reality. (A political problem!)
The third easiest way to disagree with someone is to not actually hear what they are saying. (A filtering problem!)
The hardest way to disagree with someone is to come to understand that they see the world differently than we do, to acknowledge that they have a different worldview, something baked in long before they ever encountered this situation. (Another marketing problem, the biggest one).
There actually are countless uninformed people. There are certainly craven zealots. And yes, in fact, we usually hear what we want to hear, or hear what the TV tells us, or hear what we expect, instead of hearing what was said, and the intent behind it. Odds are, though, that we will make the change we seek by embracing the hard work of telling stories that resonate, as opposed to dismissing the other who appears not to get it.