The long-term outcomes from the Abecedarian Project are equally informative. The children in the preschool treatment group continued to receive benefits from their participation in the early childhood program – lasting throughout their school years and into early adulthood. During the school years, and in comparison with the control group, the children who participated in the Abecedarian preschool intervention had:
- significantly higher achievement scores in reading and maths at ages eight, 12, 15 and, even later, at 21 years.
- a lower rate of grade retention (i.e., failing at least one grade) that was almost half the rate for the control group
- a lower rate of placement in special education by age 15 – only 12% of the treatment group versus 48% of the control group were placed in remediation or intervention programs.