Given the evidence presented earlier that early-onset disorders have more negative outcomes, it might be important to intervene in younger children's lives instead of waiting until adolescence. Hawkins, Catalano, Kosterman, Abbott, and Hill (1999) used a non-randomized controlled study to evaluate the Seattle Social Development Project, a package of interventions that included in-service training for teachers, developmentally appropriate parenting classes (e.g., child behavior management skills), and developmentally adjusted social competence training (problem solving and peer pressure resistance) for children. Children were given training in grades 1-6, while parents were trained when the children were in first through third and fifth through sixth grades. Teachers received five days of training each intervention year. Even though only 46% of the parents in the full-intervention group completed the parent training, intervention group students reported fewer instances of violent delinquent acts, heavy drinking, sexual intercourse, having multiple sexual partners, being pregnant or causing pregnancy than the control group at a follow-up at 18 years of age. Unfortunately, the evaluation did not determine which particular components of the intervention were most important or if all of the components were equally necessary.