Since 1986, when disorganized attachment was first defined by Mary Main and Judith Solomon, a great deal of interest has been shown in this addition to the standard Ainsworth classification system. This groundbreaking volume brings together eminent researchers and clinicians to present current, original theory and data on the nature of disorganized attachment, its etiology, and its sequelae. Contributors report on the social, psychological, and biological contributions to disorganization. Longitudinal findings are presented on developmental outcomes in middle childhood; special populations are examined, including children with disabilities; and new assessment methodologies are described. Advancing our understanding of a significant subgroup of infants and children with attachment-related difficulties, the volume represents an important contribution to the empirical attachment literature.