Most of us adhere to at least many social "norms". These aren't decided by some official body of course. We put the fork on the left in a place setting. I used to put it on the right because I'm right handed. We don't chew with our mouths open. We don't use certain words in "polite company". We take our hate off at the table. We face forward in an elevator.
It goes on and on, just a means of playing well with others. The penalty of noncompliance can be not being invited over any more, which for some no doubt is no penalty at all. I personally find it easier to "get along" in life by complying with most such norms.