Lawrence Kohlberg was an American psychologist best known for his theory of moral development. Born in 1927, he focused on how individuals progress through different stages of moral reasoning. His work built on the ideas of Jean Piaget, emphasizing that moral understanding evolves as people grow and encounter new experiences. Kohlberg identified six stages of moral development, grouped into three main levels: pre-conventional, conventional, and post-conventional. His research involved presenting moral dilemmas to participants and analyzing their reasoning. This framework has been influential in education, psychology, and ethics, providing insights into how people make moral decisions throughout their lives.