Publication Date



Open access

Degree Type


Degree Name

Master of Science (MS)


Psychology (Arts and Sciences)

Date of Defense


First Committee Member

Daryl B. Greenfield

Second Committee Member

Rebecca J. Bulotsky-Shearer

Third Committee Member

Maria S. Carlo


The current study examined the influence of classroom age composition (the variability in ages of children in the classroom) on low-income preschool children's rates of change in multiple domains of school readiness. The sample consisted of 4,417 preschool children enrolled in 207 classrooms in a large, diverse Head Start program. Children were assessed throughout the year on four school readiness domains: emergent literacy, emergent numeracy, social and emotional skills, and approaches to learning. Multilevel modeling was employed to examine the main effect of classroom age composition as well as the interaction between classroom age composition and child's age as predictors of children's rates of change in these school readiness domains. Results showed that classroom age composition did not uniformly influence rates of change in school readiness for all children. Instead, a significant interaction between child's age and classroom age composition indicated that younger children developed skills in the domain of approaches to learning at an increased rate when placed in classrooms with a large age composition (i.e., in classrooms with a greater degree of age-mixing). This study extends literature focused on identifying classroom structures that promote positive development of school readiness skills, particularly for at-risk children.


Classroom Age Composition; Head Start; School Readiness; Developmental Psychology