The stages of moral development were proposed by Lawrence Kohlberg, a psychologist who conducted research on the development of moral reasoning. Kohlberg's theory proposes that individuals progress through six stages of moral development, which can be grouped into three levels:

1. Pre-conventional level: This level of moral development is focused on self-interest and personal gain. The two stages within this level are:

• Stage 1: Obedience and punishment orientation - individuals at this stage are motivated by avoiding punishment and obeying authority figures.
• Stage 2: Instrumental purpose and exchange - individuals at this stage are motivated by self-interest and may make decisions based on what they can gain for themselves.

2. Conventional level: This level of moral development is focused on societal norms and expectations. The two stages within this level are:

• Stage 3: Interpersonal relationships and conformity - individuals at this stage are motivated by a desire to be accepted by others and to maintain social norms and expectations.
• Stage 4: Social order and maintaining the system - individuals at this stage are motivated by a desire to maintain social order and adhere to laws and regulations.

3. Post-conventional level: This level of moral development is focused on universal ethical principles and values. The two stages within this level are:

• Stage 5: Social contract and individual rights - individuals at this stage are motivated by a belief in social contracts and the importance of individual rights and freedoms.
• Stage 6: Universal principles and ethics - individuals at this stage are motivated by a commitment to universal ethical principles, such as justice, equality, and human dignity.

It is important to note that not all individuals progress through all stages of moral development, and individuals may progress through the stages at different rates or may become stuck at a certain stage. Additionally, cultural and societal factors may influence an individual's moral development. Nonetheless, Kohlberg's theory of moral development provides a framework for understanding how individuals develop moral reasoning and ethical decision-making capabilities.