One of the important theories of moral developments was proposed by

Lawrence Kohlberg (1927–1987): proposed one of the most influential theories of moral development, expanding on Jean Piaget’s work.

Key idea: Kohlberg described how moral reasoning develops in stages and organized these stages into three main levels.

1. Pre-conventional level: moral reasoning is based on avoiding punishment and seeking rewards (obedience and self-interest).

2. Conventional level: moral reasoning is guided by social norms, approval, and maintaining social order (conformity and law-and-order).

3. Post-conventional (principled) level: moral reasoning is based on abstract ethical principles and the idea of social contracts or universal human rights.

Note: Kohlberg emphasized moral reasoning rather than moral behavior; his theory has been highly influential in psychology and education, though it has also faced criticism (for example, for potential cultural bias and for focusing more on justice-based reasoning).