Teaching by example would be one kind of social pressure, would it not? There are clear social signals involved. I don't think people should go around insulting each other, but I also don't think that you should keep quiet when someone is clearly in the wrong. You should speak up, if you have the good taste to know what you are talking about, and you have legitimate points that you can back up. I'd much rather have someone school me with expert power than oppress me with coercive political power.I'm pretty sure reality already exists for that purpose and if people can't learn a lesson the hard way, it was either academic or there's no way they would have learned it the easy way. Parents are another source of knowledge. You know, when you're NOT an adult who doesn't like being told what to do by strangers who think they're superior to you. Hell, most kids don't even like that. Why waste your breath?
The best way to teach is by example, anyway.