People in positions of power and authority are expected to behave in a manner which does not put those with less power in danger. And when there are no written laws, there are often unspoken boundaries. Friends do not betray friends. Spouses remain true to each other. Parents nurture offspring, and do not abuse their trust.
Police officers protect and defend.
Well, not always. Everyone does, at one time or another. We have lied to our children about what is important in life. We have lied, not just with our words, but with our actions. Adults have blurred the boundaries of relationships in many ways, both between adults, and between adults and children.