What the work claims
Moral reasoning develops through six stages, grouped into three levels—pre-conventional, conventional, and post-conventional—in a fixed sequence reflecting increasing complexity of justification.
How it was done
Kohlberg used the Moral Judgment Interview to present hypothetical dilemmas like the Heinz dilemma. He evaluated participants’ reasoning structures—not their choices—against scoring guidelines he built around complexity, abstraction, and perspective-taking. He followed 72 boys from Chicago longitudinally for over a decade. He later extended the work cross-culturally in Mexico, Turkey, and Taiwan.
What holds up
The method holds up as a disciplined attempt to codify moral justification into comparable response categories. The longitudinal design with repeated interviews and the cross-cultural extension provide empirical grounding for sequence claims within the studied cohorts. The scoring guidelines were applied consistently across contexts described.
What does not
The work does not establish that the six stages are universal, invariant across all populations, or predictive of actual moral action. It does not show that post-conventional reasoning is more ‘moral’, nor does it validate the stages as biologically or cognitively necessary. Nothing in the material supports claims about gender, neurology, policy, or intervention.
Why it matters beyond the lab
It created the first replicable, interview-based metric for moral reasoning—shaping decades of psychology, education, and legal development research. Its influence persists in how we frame ethical cognition, even where its assumptions have been contested or narrowed.
Is it worth your time
Yes—if you need to understand how moral reasoning was first operationalised as a measurable, stage-like construct. No—if you assume the stages describe universal moral behaviour, predict real-world conduct, or map cleanly onto age, culture, or education.