New tools, new insights: Kohlberg's moral judgement stages revisited

In this paper, four sets of data, collected by four different research teams over a period of 30 years are examined. Common item equating, which yielded correlations from .94 to .97 across datasets, was employed to justify pooling the data for a new analysis. Probabilistic conjoint measurement (Rasch analysis) was used to model the results. The detailed analysis of these pooled data confirms results reported in previous research about the ordered acquisition of moral stages and the relationship between moral stages and age, education, and sex. New findings include: (1) empirical evidence that transitions between "childhood" and "adult" stages of development involve similar mechanisms; (2) support for the notion of stages as qualitatively distinct modes of reasoning that display proper-ties consistent with a notion of structure d'ensemble; and (3) evidence of a stage between Kohlberg's stages 3 and 4. Consistent with reports from earlier research, the relationship between age and moral development is curvilinear. The relationship between educational attainment and moral development is linear, suggesting that educational environments have an equivalent impact across the course of development. Older males have slightly higher scores than older females after age and education are taken into account (accounting for 0.3% of the variance in moral ability).