Adolescents (ages 13–17) experience a great deal of change in their social environment and social roles during the transition to adulthood, and these changes are likely to negatively influence healthy behavior trajectories. While living with parents, adolescents face relatively few threats to healthy behaviors: typically, adolescents living with a parent or guardian are subject to school and home sanctions if they smoke or binge drink, are monitored by parents to eat healthfully and sleep adequately, and live in an environment where norms among peers and parents support avoidance of drinking and smoking.