It's easier to build rapport in person because sincerity and good intentions are harder to fake (signalling), which makes it easier for people to accept both good and bad arguments. Misunderstandings and potential insults can be corrected real time judging non-verbal communication, so criticism is both easier to give and receive if participants have benign intentions.
Textual online discussions remove most signalling required for this kind of immediate mutual trust, and I'm not sure much can be directly done about that aside from avoiding obvious insults and bluntness if we keep the medium the same. Emoticons don't work that well because a lot of real life signalling is involuntary which makes it more reliable. I suppose meetups work against this somewhat, since people can do preemptive signalling offline. Slowly building a trustworthy reputation should work too. I suspect for rapport reasons downvoting people you want to persuade would not be a great strategy, but perhaps some people think we're above that.
Changing your mind and admitting you're wrong are different things, and the former should be more important to optimize.
Textual online discussions remove most signalling required for this kind of immediate mutual trust
This comment surprised me even though I think it's probably true, because I instinctively interpret "being textually articulate" as a signal of being trustworthy, or at least worth listening to. I'm curious if anyone else here does the same, and if so, how long they've been communicating online (~16 years). I think the two might correlate.
When I was younger, I thought that conversations in real life were much more likely to promote true beliefs and meaningful changes than conversations online, because people in real life were only willing/able to cite evidence they were actually confident in, while those online were able to easily search for arguments favoring their position.
While this is obviously wrong—the concept that people in real life only cite evidence they are justifiably confident in is comically false—I do think the dichotomy illustrated there is interesting. One thing I've noticed is that in general the "rigor" of discussions online is higher (in terms of citations, links to external content, etc.), but that conversations in real life seem still much more likely to actually change people's minds.
I have noticed this effect in both myself and others—what do you think is going on here, and how do you think we might circumvent it? If online discussions could be made more effective at causing people to actually change their minds, this could potentially prove extremely useful.