The effectiveness of early intervention: examining risk factors and pathways to enhanced development.

In this paper we examine the effectiveness of early intervention, especially vis-à-vis (a) child and family risk factors and (b) the pathways to enhanced child and family development. To address these issues we draw on findings from the Infant Health and Development Program (IHDP) for low-birth-weight premature infants. The data we present reveal the considerable effectiveness of the IHDP intervention in enhancing several aspects of early and later child and family development. The findings also illustrate the importance of looking beyond intervention group differences to examine the extent to which early intervention effects are more pronounced for some children and families than others and to examine the processes underlying intervention effects (e.g., exactly how do early interventions change children and families?). For example, both initial and longer-term IHDP intervention effects varied by both characteristics of the children and characteristics of their families. Our data also provide some insight into the processes by which intervention effects may have occurred. We conclude our consideration of these many complexities with suggestions for practice, social policy, and future research.