Socially complex peer play and preschoolers' prosocial judgment: the role of earlier mental state knowledge

Socially complex peer play may provide opportunities for children to coordinate perspectives, negotiate roles, and respond to others' needs, but its association with prosocial judgment may differ according to children's social-cognitive resources. This small-scale longitudinal study examined whether mental state knowledge assessed at age 4–5 conditioned the concurrent association between socially complex peer play and prosocial judgment assessed at age 5–6. Participants were 35 children from a private nursery school in Japan. Mental state knowledge was assessed using a false-belief task. At age 5–6, children completed helping and sharing judgment tasks, and their free play was observed naturalistically across repeated focal-child observations. Socially complex peer play was indexed by the combined proportion of associative and cooperative play. Hierarchical regression analyses showed that the interaction between earlier mental state knowledge and socially complex peer play significantly predicted sharing judgment. The corresponding interaction for helping was positive but did not reach the conventional significance threshold. Sensitivity analyses using heteroskedasticity-consistent standard errors supported the sharing result. Given the modest sample size, the findings should be interpreted as preliminary. They suggest that the association between socially complex peer play and prosocial judgment may differ according to children's earlier social-cognitive resources.