The Project on Human Development in Chicago Neighborhoods (PHDCN) was a large-scale, interdisciplinary study of how families, schools, and neighborhoods affect child and adolescent development. One component of the PHDCN was the Longitudinal Cohort Study, which was a series of coordinated longitudinal studies that followed over 6,000 randomly selected children, adolescents, and young adults, and their primary caregivers over time to examine the changing circumstances of their lives, as well as the personal characteristics, that might lead them toward or away from a variety of antisocial behaviors. Numerous measures were administered to respondents to gauge various aspects of human development, including individual differences, as well as family, peer, and school influences. One of the measures that composed the Longitudinal Cohort Study was the Youth Self Report (YSR). The YSR protocol, a self-administered survey, was first developed by Thomas M. Achenbach and was derived from another widely-used standardized measure in child psychology, the Child Behavior Checklist (CBCL). The YSR was designed to assess the emotional and behavioral problems in adolescents (aged 11 to 18) in a standardized format. The PHDCN version of the YSR was administered to subjects belonging to Cohorts 12 and 15 of the Longitudinal Cohort Study. It assessed internalizing (i.e., anxiety, depression, and overcontrolled) and externalizing (i.e., aggressive, hyperactivity, noncompliant, and undercontrolled) behaviors. Eight sub-scale symptoms (Withdrawn, Somatic Complaints, Anxiety and Depression, Social Problems, Thought Problems, Attention Problems, Aggressive Behavior, and Delinquent Behaviors) were also measured.