Class Peer Network and Heterogeneous Intervention Effects on Children's Social Information Processing Skills: Evidence From Let's Be Friends (Shaanxi) Trial 2

Children's social information processing (SIP) skills notably affect their aggressive behaviour. Previous randomized trials have demonstrated the positive effects of the ‘Let's Be Friends’ (LBF) intervention in enhancing children's SIP skills and promoting prosocial behaviours. However, little attention has been paid to peer influence in the Chinese administrative class system. Taking LBF (Shaanxi) Trial 2 (LBF2) as an example, this study used a hierarchical linear model to examine the spillover effect and heterogeneous influences of the programme on children's SIP skills across classes with varying average SIP levels at baseline in rural China. The final analysis included 712 children, with 343 (48%) in the LBF2 group and 369 (52%) in the control group. Of the total, 359 (50.4%) were boys and 353 (49.6%) were girls, with an average age of 8.68 years. The findings revealed that peer interventions through LBF2 in classes could generate more spillover effects than individual interventions for children. The LBF2 intervention exhibited discernible compensatory effects in classes with lower average levels of SIP skills and demonstrated its potential to promote the balanced development of all children's SIP skills in various class settings. It highlights the importance of considering class-level SIP averages when designing targeted interventions.