Lawrence Kohlberg was one of the first serious thinkers to study and know about a person's ability to deal with ethical issues which could develop in later life and also whether education could affect that development (Source: Can Ethics Be Taught).
Kohlberg developed a theory of moral reasoning, which according to him was the basis for ethical behavior and has three major levels split into six identifiable stages of moral development as shown below:
The Stage 1 is a heteronomous orientation focusing on avoiding breaking rules that are backed by punishment, obedience for its own sake and avoiding the physical consequences of an action to persons and property (Source: Studies in moral development and education).
The Stage 2 orientation focuses on the instrumental, pragmatic value of an action. Reciprocity is of the form. The Golden Rule becomes, "If someone hits you, you hit them back". Thus one follows the rules only when it is to someone's immediate interests. What is right is what's fair in the sense of an equal exchange, a deal, an agreement with his (her) own interest (Source: Studies in moral development and education).
At Stage 3 individuals are aware of shared feelings, agreements, and expectations which take primacy over individual interests. ...