Preschools Reduce Early Academic Achievement Gaps

Tucker-Drob, E. M. (2012). Preschools reduce early academic-achievement gaps: A longitudinal twin approach. Psychological Science, 23(3), 310-319.

Despite documented associations between social class and school quality, children from impoverished backgrounds still stand to benefit from preschool education. In fact, studies have shown that children from low-income homes may obtain greater gains from preschool during the year before kindergarten than do higher income children. Tucker-Drob (2012) sought to determine whether differences between children who do and do not attend preschool are a result of the preschool experience or the result of a selection bias — that is pre-existing differences that determine preschool enrollment. The participants in this study were 600 sets of twins. Variation due to genes, nonshared environmental influences, and shared environmental influences was estimated for the monozygotic and dizygotic twins and measures of income, and parental stimulation of cognitive development were taken. Using a longitudinal design, mental ability and academic achievement was measured at ages 2, 4, and 5. At age 5, when compared with children who did not attend preschool at age 4, shared family environmental influences accounted for significantly less of the variance in math and reading scores for those who did attend preschool at age 4. In addition the effect of shared environmental influences on mental ability at age 2 did not differ for those who did and did not attend preschool. These results indicate that gains in academic achievement were due to preschool experiences rather than a selection bias.

Making Connections

Academic achievement
Longitudinal studies
Nature and nurture
Selection bias
Twin studies

Media Supplement

An economist discusses the benefits of preschool in this Planet Money podcast. [18 min 4 sec] (start at 3:10)