Lawrence Kohlberg was one of the first to research the moral reasoning of adolescent boys and (later, college students) while at the University of Chicago in 1958 (Evans, 2010). He based his theory on Jean Piaget's three stages of moral development and identified three additional stages of development and revised Piaget's stages. To develop his theory he used a series of hypothetical dilemmas and focused on the process of how individuals make moral judgments and not the content of these decisions.