Lawrence Kohlberg (1958) agreed with Piaget's (1932) theory of moral development in principle but wanted to develop his ideas further.
He used Piaget’s storytelling technique to tell people stories involving moral dilemmas. In each case, he presented a choice to be considered, for example, between the rights of some authority and the needs of some deserving individual who is being unfairly treated.
By studying the answers from children of different ages to these questions, Kohlberg hoped to discover how moral reasoning changed as people grew older. The sample comprised 72 Chicago boys aged 10–16 years, 58 of whom were followed up at three-yearly intervals for 20 years (Kohlberg, 1984).
Each boy was given a 2-hour interview based on the ten dilemmas. What Kohlberg was mainly interested in was not whether the boys judged the action right or wrong, but the reasons given for the decision. He found that these reasons tended to change as the children got older.
He identified three distinct levels of moral reasoning each with two sub-stages. People can only pass through these levels in the order listed. Each new stage replaces the reasoning typical of the earlier stage. Not everyone achieves all the stages. . . .