How we change what others think, feel, believe and do
Once we have decided that we believe something, we will tend to keep on believing it, even in the face of disconfirming evidence.
Particularly if other people know of our belief, it can be embarrassing to climb down from our previous assertions. It is also difficult to remove a belief which has been woven into a wider web of belief, without disturbing those other beliefs.
Ross, Lepper and Hubbard (1975) asked experimental participants to look at suicide notes to determine which were real. A third each of the participants were told that they were right 10, 17 and 24 out of 25 times. They were then told that they had been lied to and asked to estimate more correctly. Those who had been told higher numbers continued to guess high.
Do not get people to describe their beliefs publicly if you want to change them.
Get people to describe the beliefs you want them to keep publicly.
Pay attention to evidence. Avoid skipping past what you see just because you have already concluded something.