The many changes occurring during period of adolescence and the rapidity and complexity of their interaction frequently result in periods of stress in an attempt to cope successfully with these alterations. This transition period is a critical time in which youth settle many developmental tasks, including strengthening and expanding self-concepts, forming stable intimate relationships, making career decisions, and achieving independence from parents. However, the shift in the adolescent's social world from family to peers does not lessen the importance of the family in the adolescent's life. Family closeness has been confirmed as the most important protective factor against certain high-risk behaviors such as smoking, alcohol and drug use, and early initiation of sexual intercourse.