Douglas W. Nangle, PhD, is Professor and Director of the Doctoral Program in Clinical Psychology at the University of Maine. He has published extensively in the areas of social skills assessment and treatment, child and adolescent peer relations, and cognitive-behavioral treatments. An award-winning teacher and mentor, he has advised, taught, and provided clinical supervision for doctoral students for more than 20 years.His research examines the influence of close peer relationships on the psychological adjustment of children and adolescents. Ongoing investigations include the further validation of a measure of adolescent heterosocial competence, a short-term longitudinal examination of the effects of three dyadic interaction processes (i.e., negative feedback seeking, excessive reassurance seeking, and co-rumination) within girl friendships on the onset and worsening of depressive symptoms, and a developmental test of the protective value of children’s friendships. Other areas of interest include social skills assessment and intervention, ADHD, aggression, and cognitive behavioral treatments. As a licensed psychologist, Dr. Nangle also provides supervision for students in the doctoral program, directs an ADHD clinic, and maintains a forensic psychology practice, in which he serves as a consultant for the Maine State Forensic Service, Department of Health and Human Services, and the Child Abuse and Neglect Evaluators Project.