Sure, this is the obvious takeaway if you are solely interested in how to persuade others and advance your agenda. But the reason why personal experiences are better at bridging moral/political divides is because shared experience makes it possible for to hear another viewpoint. If all you get from this study is an improved approach to advancing your issue, that's a shame.
I have lots of shared experiences with my parents, but there is no bridging our moral/political divide. The assumptions they use in their model of the world, as well as the data, are completely inappropriate. At least to accomplish my goals.
I think unless conversations agree on the assumptions and agree on the data sources and data itself, and even the logic, it’s going to end in disagreement. My parents can hold conflicting viewpoints simultaneously, in sentences one after another, and have no problem with it.
"My parents can hold conflicting viewpoints simultaneously, in sentences one after another, and have no problem with it."
They probably say the same about you. The hard truth is that most people hold conflicting opinions. It usually takes about 20 years of being an adult to come to this realization.
Also opinions and perspectives change. I was quite liberal, politically, in my 20s. In my 50s I'm quite conservative, though I would never have thought that could be the case when I was 22.
That seems to be fairly common. School curriculum tends to have a brainwashing element to it. Also, each generation thinks it has all the answers. I remember discussions with older relatives, trying to convince them of something. They turned out to be right more often than not.
Viewpoints are typically the intersection of a number of values. Your interpretation of conflict might just be a function of how your values are weighted vs those of your parents.
...shared experience makes it possible for to hear another viewpoint.
That's specifically why personal experience is a persuasion tool and an effective one - which isn't an absolute bad thing but also doesn't make it an inherently good thing.
The average person, debating on the Internet or off, tends to start in an intensely emotional state. Giving your own personal experience backs them down from that intense emotional state.
Once the person has backed-down a bit you can give your pitch and your pitch can be anything, either a plea for rational inquiry into the situation or your own intensely manipulative, emotional and off-kilter claims.
I personally try to go from polarized emotional shouting matches to "let's make a model of the world and consider what makes sense in it" approaches. I think if you can get someone to start thinking about things that way, you have given them thinking-tools and not simply openness.
Something to think about is that simple openness is by no means an inherently good thing. A lot of New Age ideologies talk about the need to stay open with upshot that people open themselves to all sorts of poisonous and delusional crap. Being open but selective in what you let in is much better.
