FWIW, from what I understand this is actually how it works. People do learn vicariously, by watching and through example, but only if the lessons aren't overridden by their other experiences of life around them. i.e. if you're brought up in a environment which contradicts what you see, then you instinctively treat it as something which doesn't reflect on yourself, and don't model your behaviour on it.

Two famous studies in the area are the Bandura study of vicarious learning with Bobo dolls (which found children behaved with more violence after watching violence), and the Charlton study on St Helena (which has very low levels of violence, which did not increase with the introduction of satellite TV, apparently because the example of their peers and parents over-rode what kids saw on TV).

This make you wonder whether ultraviolence could actually be better than violence in context. If you show some crazy movie where hundreds of zombies have their heads blown off, or trail around various body parts while dragging themselves along the floor after being attacked with a chainsaw, you would tend to categorize that as something completely outside your experience (!), and it probably would have little effect, but if you show a film intended to sincerely address problems that kids are having in their everyday lives, and you show someone reacting to an insult with low level or moderate violence, that's something they could actually pick up and think 'this is how people are expected to behave'.