Lawrence Kohlberg's most famous research tool poses a story: a man named Heinz can't afford a drug that could save his dying wife, the pharmacist who invented it refuses to lower the price, and Heinz is left deciding whether to steal it. Presented with this dilemma, most people expect the interesting data to be whether respondents say Heinz should steal the drug or shouldn't. Kohlberg's actual insight was that the yes-or-no answer barely mattered at all — what revealed a person's stage of moral development was the reasoning behind whichever answer they gave.
Six stages, three broad levels
Kohlberg proposed that moral reasoning develops through six stages, grouped into three broader levels. At the earliest, pre-conventional level, moral reasoning is centred on consequences to oneself — Heinz shouldn't steal because he might get caught and punished, or should steal because his own need for his wife outweighs the risk. At the conventional level, reasoning shifts to social approval and rule-following — Heinz should or shouldn't steal based on what a good husband would do, or what the law requires, with reasoning anchored in maintaining social order and relationships rather than direct personal consequences. At the most advanced, post-conventional level, reasoning appeals to abstract ethical principles that can, in Kohlberg's framework, stand above and even conflict with existing laws — the value of human life outweighing property rights and legal statutes, reasoned from first principles rather than social convention.
Gilligan's challenge: whose moral voice was actually being measured
Carol Gilligan, a former student and later critic of Kohlberg, argued his stages reflected a specific, culturally masculine conception of morality centred on abstract justice, rules, and individual rights — and that Kohlberg's original research sample, largely male, had built a framework that systematically scored a different, equally valid moral orientation as less developed. Gilligan proposed that many people, and she argued women in particular given differing socialisation, reason through an "ethic of care" instead — prioritising relationships, context, and responsiveness to others' specific needs over abstract, universal principles applied uniformly. Her critique reframed Kohlberg's stages not as a neutral, universal developmental ladder, but as one particular moral orientation Kohlberg had mistaken for the only mature one.
What we're still unsure about
That Kohlberg identified real, observable patterns in how moral reasoning tends to develop and become more abstract with age is broadly supported by subsequent research, though the strict, universal, invariant sequence he originally proposed has been revised considerably since. Gilligan's specific claim that care-based reasoning is primarily a gendered difference, rather than one of several reasoning styles available to anyone regardless of gender, remains genuinely debated — later research has found the ethic-of-care orientation in men as well as women, which complicates the original framing of her critique even while her broader point about Kohlberg's framework being incomplete is widely accepted.
This sits inside Moral Development (Kohlberg & Gilligan), one of seven topics in Developmental Psychology, one of four domains in Psychology, one of seventeen subjects the app can quiz you on.