As a group, adolescents are healthy people. They have survived the vulnerable years of early childhood and are decades away from the degenerative diseases of old age. Threats to their health stem primarily from their behavior. Health is something adolescents tend to take for granted. Their energies are directed toward achieving popularity, autonomy from adults, success in school or sports, satisfying romantic and platonic relationships, and confidence in themselves.
Families differ in size, composition, resources, history, and cohesiveness.
Data are gathered from adolescents themselves, from their parents, siblings, friends, romantic partners, and fellow students, and from school administrators. Already existing data bases provide information about neighborhoods and communities. With data from so many sources, new types of analyses are possible, involving both separate and joint effects of surroundings and circumstances on behavior and health status. The Add Health study is longitudinal, with adolescents interviewed for a second time at a one-year interval.