The codevelopment of moral and conventional normative stances from 2.5 to 3.5 years: A cross-lagged panel approach.

Developmental science has accumulated considerable evidence that by 2 to 3 years of age, children begin to appreciate the obligatory nature of different social norms and distinguish between moral and conventional transgressions. However, little is known about the early ontogenetic trajectories of normative stances in the moral and conventional domains. Theoretical considerations point to three open questions: (1) Do young children's reactions toward transgressions of moral and conventional norms show increasing differentiation over this age period? (2) To which extent are young children's moral and conventional stances longitudinally stable? (3) Do early moral and conventional stances relate to each other in development? This longitudinal study presented 2.5-year-olds and 3.5-year-olds (N = 93, 45 females, predominantly White, mostly middle to high socioeconomic status) with the same established moral (i.e., harming others, destroying others' property) and conventional (i.e., sorting objects incorrectly) transgressions enacted by puppet characters. Children's spontaneous protest behavior and acceptability judgments were recorded. The relation between 2.5-year-olds' moral and conventional judgment (r = .78) decreased in 3.5-year-olds (r = .30). Moral protest (β = 0.403), but not conventional protest (β = 0.130), showed longitudinal stability. Conventional judgment of 2.5-year-olds related to 3.5-year-olds' moral judgment (β = 0.480). These findings demonstrate that young children's reactions toward moral and conventional transgressions show signs of differentiation regarding acceptability judgments and signs of stability regarding moral, but not conventional, protest behavior. This supports theoretical notions suggesting increasing differentiation and stability as central developmental processes in young children's emerging appreciation for social norms. (PsycInfo Database Record (c) 2026 APA, all rights reserved).