Birthdate Effects on School Performance and Adjustment: A Longitudinal Study

The effects of age at school entry on school performance and adjustment were examined by comparing six birthdate groups, each representing two months of the calendar year of school entry. School performance measures were tests of cognitive skills at school entry, parent and teacher ratings of performance at grade 3, and tests of aptitude and achievement at grade 4. School adjustment variables were ratings of behavioral and emotional functioning by parents at school entry and grade 3 and by teachers at kindergarten and grade 3. The use of school-based services was also assessed. Results indicated age group differences on cognitive ability at school entry, with the youngest group having the lowest scores and the oldest group having the highest scores. There were no age differences with respect to performance and adjustment in subsequent years.