Peer group age composition. Associations with children’s engagement in childcare

This observational study investigated associations between classroom age composition and 3-year-olds’ engagement in Swiss mixed-age childcare, accounting for multiple contextual and individual factors. Using the inCLASS tool, observers rated 3-year-olds’ engagement with caregivers, peers, and tasks across 407 observation cycles with 54 children. Situational age composition was operationalized by four indicators: peer group age range, median age, number of infants (<18 months), and number of children older than 4 years per cycle. Multilevel structural equation models revealed no significant associations between age-composition indicators and engagement quality. Thus, age differences neither advantaged nor disadvantaged children’s social behavior in childcare. Instead, situational activity setting, group size, number of caregivers, and peer group stability emerged as significant predictors of engagement. Social skills and child sex were also linked to observed behavior. We discuss why prior findings on age composition are mixed and highlight the need for further evidence on how mixed-age contexts shape early social and learning outcomes.