The Abecedarian Project found that low-income infants who were randomly assigned to participate in high-quality child care from infancy through age 5 experienced significantly greater academic success than peers who did not attend the program, finished more years of schooling, and as adults had improved employment and life prospects.

The NICHD Study of Early Child Care is the most comprehensive child care study conducted to date in the United States. The NICHD data shows that higher-quality child care is linked with higher scores on standardized tests of math and reading achievement and of memory through third grade. More hours spent in care each day was associated with poorer work habits and poorer social skills in third grade.

This study—perhaps the most well-known of all High/Scope research efforts—examines the lives of 123 African Americans born in poverty and at high risk of failing in school. The study has found that adults at age 40 who attended the quality Perry preschool program had higher earnings, were more likely to hold a job, had committed fewer crimes, and were more likely to have graduated from high school than adults from the same group who did not attend preschool.