What is the best style of debate for persuasion?

[HumbleThinker]

@Salvor

This was a question that came up in another post, but it seems like a hard problem and I don’t have the answer.

What style and form of debate is the best at persuading people, and potentially the debaters themselves?

I wonder if the last requires a NON public forum to eliminate the need to save face in public? Has there ever been a televised debate where one side conceded that the other side was right?
Is calling it a “debate” in the first place counter productive? Would calling something a discussion be more conducive to dialog and hashing ideas out?
I used to think it was always best to have hyper intelligent people that were extremely knowledgeable about the subject was always ideal, and I think that is still better than having people who do not know as much, but I think that alone might not be enough. I remember reading recent research that suggested that greater knowledge of a subject INCREASED polarization on a topic, likely because people with greater knowledge can better select the bits that conform to their world view. The one group that was more resistant to this were the science “curious” that were more open to looking at arguments and data that went against their own views. So would having debaters that were more like the latter crowd be more conducive to persuasion?

Are formal debates with moderators inherently inferior? The intelligence squared debates are structured but are fairly decent in my mind, but political debates with moderators are just so much fluff and talking to the camera.
What is the answer? Answers?

I think for anyone to be convinced to change their mind, they must have some personal investment in the discussion. I’d venture that for most people, dispassionately finding the truth of a matter doesn’t cut it; at best, they will ultimately be swayed by their unconscious biases despite their best intentions. But if they have a relationship with someone with an opposing view or someone the matter at hand affects, now they have something invested in the outcome of the discussion.

As a concrete example, take gay marriage. There are numerous stories a few years back of people who were against gay marriage softening or drastically changing their position after realizing a family member of theirs was gay and wanted to marry someone of the same gender. I vaguely remember a study also on gay marriage a while back that suggested a door-to-door lobbyist (or whatever the actual word for those kind of people are) had an increased chance of convincing someone to support gay marriage if they first made a personal connection with that person. I believe it was later revealed that there were some methodological issues, but I personally think the general idea is on the right track. Also, I’m sure we all have teachers or other individuals who we have a strong relationship with built on respect for their thought processes.

If you respect, care for, etc. a person, you have a personal investment in that relationship. Whether to maintain that relationship or just because you put more stock in what that person says compared to the average stranger, I’d venture that you’d be more willing to change your mind based on the words of someone you have a relationship with.