When Does Sharing Cost Too Much? Peer Presence and Resource Acquisition in Young Children

This research used three sequential experiments to examine how peer social relationships (classroom belongingness and intimacy level), relative age (one-year-younger, same-age, one-year-older), and resource acquisition method (effort-based, random) influence high-cost sharing among Chinese children aged 4 to 6. Study 1 (<i>N</i> = 256, 128 boys) served as a foundational study, testing how classroom belongingness (same class, different class) and intimacy (high, low) in peer presence affect high-cost sharing. Results showed that 4- to 5-year-olds were more likely to share with high-intimacy peers, while 5- to 6-year-olds were more sensitive to same-class peers, suggesting a developmental shift toward classroom identity. Building on these findings, study 2 (<i>N</i> = 96, 48 boys) examined 5- to 6-year-olds in mixed-age classes, controlling for high familiarity and same-class peer presence. The presence of one-year-older peers significantly increased sharing, revealing a hierarchical age effect. Study 3 (<i>N</i> = 128, 64 boys) further examined the interaction between resource acquisition method and relative age. Effort-based acquisition reduced sharing, but one-year-older peer presence mitigated this effect. Findings indicate a developmental transition from intimacy driven sharing in younger children (4- to 5-year-olds) to classroom belongingness and relative age sensitive sharing in older children (5- to 6-year-olds), and show that the interaction between relative age and shared resource acquisition method critically shapes high cost sharing behavior in this age range.