Contents: Series Prologue. M.H. Bornstein, J.L. Genevro, Child Development and Behavioral Pediatrics: An Introduction. M. Papou(s)ek, H. Papou(s)ek, Infantile Persistent Crying, State Regulation, and Interaction With Parents: A Systems View. W.T. Boyce, Biobehavioral Reactivity and Injuries in Children and Adolescents. J.L. Genevro, C.J. Andreassen, M.H. Bornstein, Young Children's Understanding of Routine Medical Care and Strategies for Coping With Stressful Medical Experiences. Z.N. Kain, L.C. Mayes, Anxiety in Children During the Perioperative Period. M.S. Steward, J. O'Connor, C. Acredolo, D.S. Steward, The Trauma and Memory of Cancer Treatment in Children. N. Leffert, A.C. Petersen, Biology, Challenge, and Coping in Adolescence: Effects on Physical and Mental Health. A.H. Parmelee, Jr., Commentary: Children's Health and the Development of Social Knowledge.