For more than a quarter of a century, our research has been guided by a social-psychological framework we refer to as Problem-Behavior Theory. Derived initially from the basic concepts of value and expectation in Rotter's (1954, 1982) social learning theory and from Merton's (1957) concept of anomie, the framework was first applied in a comprehensive study of alcohol abuse and other problem behaviors in a small, tri-ethnic community in southwestern Colorado (Jessor, Graves, Hanson, & Jessor, 1968). Subsequently, the framework was revised to accommodate a major, longitudinal study of problem behavior and psychosocial development in cohorts of junior high school adolescents and college youth (Jessor & Jessor, 1977). It also provided the theoretical basis for two large-scale, national surveys of junior–senior high school youth, with a special focus on the psychosocial correlates of alcohol and drug use (Donovan & Jessor, 1978, 1983; Jessor, Chase, & Donovan, 1980; Jessor, Donovan, & Widmer, 1980).

More recently, Problem-Behavior Theory, again revised and extended, has been guiding the follow-up study of the earlier longitudinal cohorts of adolescents and youth as they have traversed through young adulthood; that is the study reported in this volume. Finally, the theory has been elaborated further to guide our most recent research involving the larger domain of health-compromising and health-enhancing behavior in youth (Costa, Jessor, & Donovan, 1989; Donovan, Jessor, & Costa, 1991; Jessor, 1984).