Can Intensive Early Childhood Intervention Programs Eliminate Income-Based Cognitive and Achievement Gaps?

By how much would an intensive two-year center-based Abecedarian-type intervention, begun at age one, close income-based gaps in cognitive ability and school readiness? To generate estimates, we draw data from the Infant Health and Development Program (IHDP), which randomly assigned a treatment consisting of the Abecedarian curriculum to nearly 1,000 low birth weight children from both higher and low-income families between ages one and three. The IHDP data are uniquely suited to developing credible evidence on gap closing because other experiments have excluded children from higher income families. We first show that treatment effects for the heavier subset of IHDP babies may well generalize to normal birth weight babies. We then use nationally representative data from the Early Childhood Longitudinal Study birth cohort to project IHDP impacts to the IQ and achievement trajectories of the U.S. national population. In keeping with the findings of prior IHDP-based studies, we show that IHDP program impacts were generally much stronger among low- than higher-income children. We project that at age three – at the end of the program – either a universal or an income-based targeted program would essentially eliminate the 1.4 standard deviation income-based gap in cognitive ability. Despite considerable fadeout of program effects, the .77 sd income-based IQ gap at age five would be substantially reduced, if not completely eliminated and that between one-third and three-quarters of the gaps in age-eight IQ and achievement would be eliminated by the early education program.