The study of morality is not new. Plato explored human ethics in ancient Greece and philosophers throughout history have debated moral dilemmas. However, psychologist and child development theorist Jean Piaget was the first to present the idea that morality is a developmental process. Psychologist Lawrence Kohlberg worked from Piaget’s theories, identifying six specific moral stages, the first four accomplished in childhood. Kohlberg believed the stages of moral development are progressive and that a person could only be in one stage at a time.
The first two stages occur roughly before age nine. It is a time when children see morality as external to them. In stage one, moral behavior is associated with obedience and moral choices are seen as good or bad. People in authority signal to children whether something is right or wrong and children are motivated to avoid punishment. If someone is bad, children believe he should be punished, and if a person is punished children will assume it is justified.
In stage two, children still desire to follow rules and regulations, but an understanding of self-interest comes into play. They start to see that what is right or wrong is relative, depending on the person's point of view, that something may be considered right if it can be justified by a personal need. In particular, they will believe they are right if their motives are important to them.
A child goes through stage three in the early adolescent years. Children are concerned with interpersonal relationships in this stage and they give more weight to motives and context. Their perspective is less self-centered and they use empathy to assess whether another person's behavior is right or wrong. They seek to gain the approval of others and desire to be seen as good.
Stage four, in the later teen years, is a time when children identify with the values of a larger society and are motivated by a sense of duty. They understand the need for social order and restraint on individual needs. They follow rules because it is necessary for a well-functioning society, not because they were told to by an authority figure. Professor Larry Nucci from the University of Illinois at Chicago points out that children need to be given the tools for moral reasoning in order to appropriately consider conventions and attitudes.