Most people learn where the boundaries of social norms are by testing them. Children spend their entire childhoods learning where the social norm ‘walls’ are. It’s their job. And the comparatively high length of the human juvenile phase (aka. childhood) is reflective of how socially complex human society is. There are so many formal and informal social rules to learn.
Children who are not given boundaries (or who are not given help to understand and recognise them) grow up with problems and, at the other end of the spectrum, children who live with very rigid boundaries (and never learn that they can be bent and twisted and creatively changed) do, too. Because one of the fundamental parts of being a human being is learning to manipulate social convention and knowing when to (successfully) bend a rule.
There are three systems that have become the primary means of communicating social norms to kids and, sadly, not necessarily in this order unless you are a super parent. Parental influence and parental systems, the media and education. Children are heavily influenced by all three of these purely on saturation grounds. I would be tempted to add ‘peer’ systems there but perhaps children instinctively don’t give the words and actions of their peers as much importance as those of adults.
Taken from The Great Courses’ Explaining Social Deviance Lecture 1: Asking the Right Questions