Key to the mission of the National Institute of Child Health and Human Development (NICHD) is answering fundamental questions about how a single fertilized cell eventually develops into a fully functional adult human being and how a multitude of genetic and environmental factors influence that process. This document details part of NICHD's strategic plan for achieving its mission, focusing on goals and objectives to guide NICHD research on biobehavioral development over the next 5 years. The document first describes NICHD's mission and outlines the strategic planning process. The introduction then presents basic concepts underlying the NICHD biobehavioral strategic plan. The first section of the document discusses 2 scientific goals of the strategic plan. The first concerns biobehavioral bases of developmental continuities and discontinuities from birth through parenthood, and includes biobehavioral influences of social behavior and socialization, influence of sex/gender throughout development, fetal behavior, understanding and facilitating learning in typically developing populations, and adolescence. The second concerns the development of individuals with disabilities and chronic diseases, including therapeutic interventions for developmental disabilities and related conditions, developmental neurobiology underlying the emergence of prosocial versus violent and aggressive social behaviors, and biobehavioral effects of the interaction between the individual, technology, and multimedia sensory experiences throughout development. The second section of the document examines research technologies and resources deemed relevant, including data collection and analysis related to neural networks and dynamic systems for analysis of development, animal models, functional neuroimaging, and brain tissue banks. The document concludes by identifying the need for predoctoral and postdoctoral training programs that integrate experiences across the many disciplines relevant to biobehavioral research and the need to create new opportunities for effective and productive multidisciplinary research endeavors. Appended is the roster of members of the strategic plan working group providing advice on the development of this document. (KB)