Another example: I regularly volunteer at conventions. Somewhere between 90 and 95% of people follow the rules without much prompting. 5-10% of people don't... but I sincerely believe that without volunteers watching, that number would go up sharply. Another reason people behave is the threat of their badge being revoked.
> "For thousands of years people lived without governments. In many parts of the world people live outside of the control of governments today. They do not all kill each other."
Hahaha no. Just no. People may not have lived under the control of formal governments, but there is always some sort of power structure. They may not have killed each other with systematic warfare, but small raids and personal violence killed a lot of people per capita.
---
Having said all that, I do think that internalizing the rules of society does far more than overt displays of power, like police or military parades; but I also think that the police play an important role in decreasing public crime. However, I also do not think that simply adding more police or increasing the harshness of enforcement will decrease public crime further.
It's all Pareto Principle.