“If you force kids to explain complex notions, such as how to balance competing concerns about rights and justice, you’re guaranteed to find age trends because kids get so much more articulate with each passing year. But if you are searching for the first appearance of a moral concept, then you’d better find a technique that doesn’t require much verbal skill… Elliot Turiel developed such a technique. His innovation was to tell children short stories about other kids who break rules and then give them a series of simple yes-or-no probe questions. For example, you tell a story about a child who goes to school wearing regular clothes, even though his school requires students to wear a uniform. You start by getting an overall judgment: ‘Is that OK, what the boy did?’ Most kids say no… Then you probe to find out what kind of rule it is: ‘What if the teacher said it was OK for the boy to wear his regular clothes, then would it be OK?’…
Turiel discovered that children as young as five usually say that the boy was wrong to break the rule, but that it would be OK if the teacher gave permission… Children recognize that rules about clothing, food, and many other aspects of life are social conventions, which are arbitrary and changeable to some extent.
But if you ask kids about actions that hurt other people, such as a girl who pushes a boy off a swing because she wants to use it, you get a very different set of responses. Nearly all kids say that the girl was wrong and that she’d be wrong even if the teacher said it was OK… Children recognize that rules that prevent harm are moral rules, which Turiel defined as rules related to ‘justice, rights, and welfare pertaining to how people ought to relate to each other.'”
-Jonathan Haidt, The Righteous Mind