This randomized trial tested whether small-group discussions about narrative fiction improve children's collective and individual moral reasoning. The sample consisted of 704 Swiss children (Mage = 10.32, 49.3% girls, 29.8% with a non-Swiss German home language), 159 discussion groups, and 51 teachers across 3 waves in 2022-2023. Data included coded discussions and essays on conflicts between fairness and group loyalty. The intervention enhanced collective reasoning, indicated by increases in student talk, questions, reasons, challenges, and build-ons (RRs = 1.37-8.62) and decreases in unreasoned claims (RR = 0.49). For individual reasoning, children in the intervention group provided more moral justifications (RR = 1.67) but not more group-based justifications and shifted to higher justification levels, including more dual-domain responses (OR = 2.05).
Gasser et al. (2026) studied this question.