A Post article, “The Reasons For Good Manners“, targeted at kids:
Take your elbows off the table.
Don’t talk with your mouth full.
Look people in the eye when you speak to them.
Write your thank-you notes.
You’ve probably heard all or most of those orders from your parents. … Good manners are a way to show others that you care about them. Manners also make it easier for everyone to feel comfortable in social situations. … “The rules of good manners are the traffic lights of human interaction. … They make it so that we don’t crash into one another in everyday behavior.” … Our distant ancestors developed behaviors to show others respect, fairness and kindness. …
Some manners are still used even though the original reason for them is largely gone. Have you ever wondered why you’re told to keep your elbows off the table? The rule dates from the Middle Ages, Forni said, when tables often were just a big board placed on a stump. Leaning on the table with your elbows could easily tip the table and make everyone lose his food! Today, it’s not good manners to text at the table, because it sends a message that you aren’t interested in the people around you.
This rationale for manners, “traffic lights of human interaction,” sure sounds good – who wants us smashing into each other willy-nilly? But a moment’s reflection shows that explanation is bull.
If people ate with elbows on the table, there would be no physical crashes. Instead, what would go wrong is that others may think you don’t care about and aren’t interested in them. Why? Because they’ve been told to interpret your elbows that way.
So yes, no-elbows-shows-caring could be a self-consistent equilibrium. Except, this is not the world we live in. There really are plenty of people out there for whom table elbows say very little, relative to other ways of inferring care and interest.
Now the above can apply more to actions that high status folks do more, regarding people who are status conscious and who tend to strictly interpret status signals. Such especially and strictly status-conscious folk will put a high priority on your always acting high status, so that they can be “comfortable” gaining status via affiliation with you. If you ever act low status, they may feel you don’t appreciate the strength of their concern for status, and regardless of how you feel they may not want to associate with you.
In our world, people from higher status subcultures tend to keep their elbows off the table more than other folks. So telling you that “people” will be offended by your table elbows is really telling you to mainly care about especially and strictly status conscious folks. They are the “people” you should count. You shouldn’t count the other people, who care less whether you always act like high status subcultures, and look more at your overall behavior toward them and their associates.
Support for strict manners seems to have weakened with increasing wealth. This could be yet another way we revert to forager like ways with increasing wealth:
Signaling discourages norm violations best when, [as with farmers,] people that matter tend to hear about norm violations, but know little else about violators. At a smaller [forager-like] scale, one norm violation will add only a small amount to what observers know about that person, and at a larger [industry-style] scale observers will probably not have heard about the norm violation. … The fact that norms are enforced best at an intermediate social density helps explain why higher-density farmers had stronger social norms than lower-density foragers, and yet even higher-density modern folk have reverted back to a weaker forager-like level of norm enforcement. (more)