You're giving a philosophical answer to what is really a scientific question. I'm interested in the mechanics of how someone may change their mind on one or more issues if people are fundamentally not persuadable on facts.
If you want to be scientific, then you will have to state your question more accurately. The way you ask it does not flow from the premise. The premise is that people are not persuaded by argument that oppose their conformational bias and in fact, furthermore, become more convinced that they are right. (It was that point I wanted to make to DSF when he asked me to provide peer reviewed data. It would wind up creating more denial of my claim.) But our lives are not solely lived in an argumentative state. We do not always have a solid wall up.
There is a Mulla Nasrudin story I don't remember well, about when the Mulla was a Doctor with a patient who the Mulla knew would resist the treatment he needed, lets say more protein in his diet like eggs, so the Mulla sat and pondered his condition out loud. You need something that is oval shaped, and it should be white, and it should come in a shell.... The patient butted in, I need eggs. Yes that would be perfect said the Mulla. What the patient really needed besides more protein was time and buy-in.
The science of the development of wisdom is ancient and well hidden, but if you seek a taste you won't do better than the stories of Mulla Nasrudin. And time, of course.
No, I'm not making that presupposition. My question didn't assume it. I'm asking about the mechanism by which people change their minds. The mechanism could be entirely a matter of outside influence. What the research says is that one form is outside influence - persuasion based on facts - is ineffective. For all I know there may be another that works perfectly well.
I posted to you elsewhere in the last day or so, that the ego can't change itself.
Kind of like what they say about fiction writing, that you want to "show" rather than "tell." So perhaps showing works where telling does not. With respect to homosexuality, my theory has always been that a shift in the portrayal of gays in popular culture which seemed to start in the 90's is responsible for changing attitudes, so that would fit.
Of course, this means that there is no way to persuade people through fact and logic. They have to come to it themselves through personal experiences which may or may not happen. Which begs the question of why anyone bothers with a discussion forum like this.
You speak as if change were a horizontal neutral phenomena, a drifting of fashion here and there. I see spiritual evolution. The drop in prejudice against gays as a result of more exposure to gays happened in part because of exposure but in part because the soul feels better. It is an increase in the capacity to love. What you call philosophical, I call the mechanics of our real human nature.
The reason to bother with a forum like this for me is not that my arguments will persuade, but that my making them here in relation to others in the way that I do, creates an experience. I try to post from an other dimension as a mind that doesn't know anything, a blind man in a land of knowers.