Theory featuring six stages of moral development advanced by American psychologist Lawrence Kohlberg.

Lawrence Kohlberg (1927-1987), an American psychologist, pioneered the study of moral development in the late 1950s. Kohlberg's theory of moral reasoning involved six stages through which each person passes in order, without skipping a stage or reversing their order. His theory states that not all people progress through all six stages.

In the 1950s, science as a whole held to the positivist belief that scientific study should be free of moral values, maintaining instead a purely "objective," value-free stance. Western psychology at that time was dominated by behaviorists who focused on behavior rather than reasoning or will. In 1958, Lawrence Kohlberg published a study that broke with both the positivists and behaviorists by presenting a theory of moral development (bringing together science and moral...