Lawrence Kohlberg was born on October 25, 1927 in Bronxville, New York. In 1973 Kohlberg developed a tropical disease, and while hospitalized in 1987, was reported missing on January 17. His body was later recovered from a marsh; however, the exact date of his death remains unknown. Rumor is that he committed suicide. Kohlberg has spent many years researching how an individual develops their own moral codes.

Kohlberg was a psychologist who applied the developmental approach of Jean Piaget, who he studied under, to the analysis of changes in moral reasoning. For his doctoral research Kohlberg studied differences in children's reasoning about moral dilemmas. Influenced by Piaget's concept of stages, Kohlberg's theory was created based on the idea that stages of moral development build on each other in order of importance and significance to the person. Each stage depends on the other from simple to the complex. Each stage also is more cognitively complex than the previous stages.

He hypothesized that moral difficulties motivated their development through a fixed sequence of increasingly flexible kinds of moral reasoning. He also helped to clarify the general cognitive-developmental view of age-related changes.

Significant works: Kohlberg, L. A. (1966) Cognitive-Developmental Analysis of Children's Sex-Role Concepts and Attitudes. in The Development of Sex Differences, edited by E.E. Maccoby, Stanford, CA: Stanford University Press,. Kohlberg, L. Stage and Sequence: The Cognitive-Developmental Approach to Socialization. In Handbook of Socialization:Theory in Research, Ed. D.A. Goslin. Boston: Houghton-Mifflin, 1969. Kohlberg, L. The Philosophy of Moral Development:Essays on Moral Development (volume I). San Francisco: Harper and Row, 1981. Kohlberg, L. Moral Development and Behavior; Moral Stages and Moralization, edited by Thomas Likona: Holt, Rinehart and Winston, CBS College Publishing, 1976.