In this part we focus on the first explanation, asking whether characteristics that predict achievement and behavior problems differ across racial/ ethnic groups. To do so, we ask what is known about factors that significantly contribute to variation in cognitive and behavioral function. Because such a review could itself span volumes, we focus in Chapter 3 on factors for which a research base is available to suggest both that the factor is significant in cognitive and behavioral development and that prevalence differs by race or ethnicity.

In Chapter 4 we review what is known from a now-extensive research base about early intervention programs and their potential to improve cognitive and behavioral outcomes for children at risk. We focus particularly on the more limited evidence available regarding the impact of early intervention on the placement of children in special education programs once they have entered school. Our early childhood recommendations appear at the end of Chapter 4.