The present study investigated the role of situational age composition in the quality of caregiving. We speciଏcally examined the impact of age range, the number of children present younger than 18 months, and median age, on the caregiver-child interaction quality under unique conditions of ଏexible and age-heterogeneous childcare. Caregiver-child interactions in nine childcare groups were observed over four mornings (N observation cycles = 144). The results from multilevel structural equation modelling showed that wide age range and a higher number of very young children present were related to lower quality of observed behavioural, emotional and learning support. Most importantly, the ଏndings suggest that the eଏects of age range can be explained by the number of children less than 18 months old. Implications for further research and mixed-age programmes' practice and policy are discussed. KEYWORDS Childcare; age composition; age range; number of infants; caregiver-child interactions There is a large research ଏeld investigating the role of childcare in children's learning, social-emotional development and psychosocial adjustment. Most studies on these associations suggest that spending time in high-quality childcare has a positive impact on child outcomes (

The present study observed 86 three-year-old children (M = 43.7, SD = 6.4) from 15 Swiss childcare groups, to investigate multiple individual and contextual contributions to toddlers’ positive engagement with peers. The children’s individual characteristics (age, sex and social skills) and childcare-related predictors (emotional and behavioural support from caregivers, and structural group features) were assessed. We employed the child-by-environment perspective and tested the hypothesis that high-quality behavioural and emotional support provided by caregivers benefits children with deficits in social abilities. Results of the multilevel structural equation modelling indicated that toddlers rated by caregivers as sociable and assertive showed more positive situation-specific peer engagement, especially with a concomitant higher quality of caregiver emotional and behavioural support. By contrast, being prosocial-cooperative was negatively associated with observed peer engagement. Thus, children’s social skills were found to be the most important factor for peer engagement in childcare settings. Important suggestions for future research are made, and practical implications are discussed.

The development of emotional competence is an important milestone during early childhood. Beyond early experience within the family, the (preschool) classroom is a relevant socialization context, and both teachers and peers may contribute to children’s emotion-related outcomes. Tracking changes in the emotion regulation competence of N = 173 preschool children (age in months: M = 43.3, SD = 6.6, 45% girls) over 6 months, the current study investigated whether and how peers contribute to differences in the development of emotion regulation in preschool classrooms. The research questions were addressed by examining three different kinds of peer groups: Classroom-level peer group, friendship group, and high-status peers. Teachers rated children’s emotion regulation competence and empathic co-regulation behavior at three assessment points. Multilevel growth modeling provided evidence that friendship-group empathic co-regulation (empathy, helping, and comforting behavior) predicted changes in preschoolers’ emotion regulation over time, confirming that friendship groups influence young children’s emotional development.