This study will assess the effectiveness of a low-intensity, low-cost, preventive intervention to reduce developmental delay and learning problems in young children. The goal is to improve home caregiving environment factors that are often suboptimal in families living in poverty; these families are often subject to social, economic, and medical risk factors. The intervention is based on a public health/primary care partnership and combines mailed parent-completed Ages & Stages Questionnaires (ASQ), a monthly mailed age-paced parenting newsletter (Building Blocks) and corresponding developmental toys (BB), and a Reach Out and Read (ROR) physician-based distribution of children's books.

Families of 4- to 7-month-old children attending a participating pediatric clinic will be randomized to either an ASQ/BB+ROR group, an ROR-only group, or a no intervention control group. Outcomes measures will be obtained at 15, 24, 36, and 48 months of age and include measures of the home environment, parenting and parent-child interaction, child language and mental development measures, and rates of referral to Early Intervention programs. Baseline and ongoing demographic information and psychosocial and biological risk factors will also be gathered to see how they relate to child and family outcomes and to determine whether certain subgroups of families are more likely to benefit from the intervention than others.