When Does Preschool Matter?

We have many reasons to invest in preschool programs, including persistent gaps in school readiness between children from poorer and wealthier families, large increases in maternal employment over the past several decades, and the rapid brain development that preschool age children experience. But what do we know about preschool education's effectiveness?In this article, Hirokazu Yoshikawa, Christina Weiland, and Jeanne Brooks-Gunn report strong evidence that preschool boosts children's language, literacy, and math skills in the short term; it may also reduce problem behaviors such as aggression. Over the elementary school years, however, test scores of children who were exposed to preschool tend to converge with the scores of children who were not. Many factors may explain this convergence. For example, kindergarten or first-grade teachers may focus on helping children with lower levels of skills get up to speed, or children may lose ground when they transition from high-quality preschools into poor-quality elementary programs. Taking a longer view, some studies have found that attending preschool boosts children's high school graduation rates and makes them less likely to engage in criminal behavior. Overall, higher quality preschool programs are associated with larger effects.How might preschools produce larger effects that last longer? Developmentally focused curricula, combined with intensive in-service training or coaching for teachers, have been shown to improve the quality of preschool instruction. Focusing on fundamental skills that both predict long-term outcomes and are less likely to be gained in the first years of school might also produce longer-lasting effects. And improving instructional quality in early elementary school and better aligning the preschool and elementary curricula may be another way to sustain the boost that quality preschool education can provide. Above all, the authors write, if we want to see sustained improvements in children's development and learning, we need to increase the quality of-not just access to-preschool education.