Kohlberg built his theory of moral development by extending the work of:

1. Kohlberg read Piaget's work on children's moral judgement. 2. He extended Piaget's account, which came about 25 years earlier, to older ages and more stages. 3. His stages follow Piaget's constructivist idea of a stage. **Why not the others:** Skinner and Freud explained morality through reinforcement and parental identification, approaches Kohlberg moved away from. _Source: Wikipedia, "Lawrence Kohlberg", section "introduction" (revision 1373893579)_