AGE OF PEERS AND EARLY-CHILDHOOD DEVELOPMENT

We examined the developmental trajectories of 59 children between 21 a nd 67 months of age randomly assigned to same-age or mixed-age child c are groups. Children were assessed at 6-month intervals with the Batte lle Developmental Inventory. Using a hierarchical linear model for ana lysis, we computed individual and group growth curves for overall deve lopment and development within 5 domains: communication, cognitive, mo tor, adaptive, and personal-social. Group assignment affected the deve lopmental trajectories for communication, cognitive, motor, and overal l development, with mixed-age children showing a quadratic trajectory and same-age children a linear trajectory. For adaptive and personal-s ocial development, however, the trajectories were similar. Across all domains, the mixed-age children tended to score higher than the same-a ge children at the younger ages, but these average differences decreas ed over time and had disappeared by age 5 years.