Why early intervention works: A reply to Baumeister and Bacharach

Abstract

In a wide-ranging critique of compensatory education, Baumeister and Bacharach [ Intelligence 23 (1996) 28 (2000)] focus most specifically on the Infant Health and Development Program (IHDP), an intervention program lasting from birth through age 3 for low birth weight (LBW) preterm infants. In response, we identify logical, methodological, and analytical inconsistencies in their critique of early intervention research and offer a balanced assessment of IHDP findings to date. Specifically, we note that Baumeister and Bacharach overinterpret null findings, selectively review the early intervention literature, engage in an inappropriate analytical appeal to variance partitioning, and evidence limited understanding of the ways in which individual differences among program participants and controls may be related to early intervention outcomes. Careful examination of the IHDP study design and database provides a clear indication of what the study accomplished and why. Alternative explanations for the absence of long-term IHDP effects are proposed.