 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 healthprimary 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 childrens books. 