Social anxiety in childhood is the focus of research in three psychological research traditions: developmental studies emphasizing dispositional constructs such as behavioral inhibition and its biological substrates; development investigations emphasizing affective-behavioral characterists (anxious solitude/withdrawal) and their parent-child and peer-relational precursors and moderators; and clinical investigations of social anxiety disorder (also known as social phobia) emphasizing a variety of etiolofical factors, diagnosis, and treatment. In this volume, we review and identify gaps in extant evidence that permit (or impeded) researchers from the three traditions to translate their core definitional constructs in ways that would facilitate the use of one another's research. Topics include: Conceptual relations between anxiety disorder and fearful temperament Factors contributing to the emergence of anxiety among behaviorally inhibited children: the role of attention Familial and temperamental risk factors for social anxiety disorder Anxious solitude, withdrawal and anxiety disorders; conceptualization, co-occurrence, and peer processes parents, peers and social withdrawal in childhood Intimately connected to this translation of constructs is a discussion of the conceptualization of core states (anxiety, wariness, solitude) and their manifestations across childhood, as well as corresponding methodologies. Extant research is analyzed from an integrative, overarching framework of developmental psychopathology in which children's adjustment is conceptualized as multiply determined such that children who share certain risks may display diverse adjustment over time (multifinality) and children with diverse risks may develop shared adaptational difficulties over time (equifinality). Finally, key themes for future integrative research are identified and implications for preventative and early intervention in childhood social anxiety are discussed. This is the 127th volume of the Jossey-Bass quarterly report series New Directions for Child and Adolescent Development. The mission of New Directions for Child and Adolescent Development is to provide scientific and scholarly presentations on cutting edge issues and concepts in the field of child and adolescent development. Each volume focuses on a specific "new direction" or research topic, and is edited by an expert or experts on that topic.