The proposed project stands to improve understanding of the role of impulsive behavior in adolescent cigarette-smoking uptake. The primary goal of this research is to cross-sectionally identify relations between two primary dimensions of impulsive behavior (i.e., inhibitory-control and delay-of-reward impulsive behaviors) as assessed by laboratory-task procedures at the different stages to becoming an adolescent smoker. The proposed study is largely correlational; however, this study is expected to generate preliminary data for future longitudinal research aimed at more firmly establishing causal or consequent relations between impulsivity and adolescent cigarette-smoking. Additionally, this study should help clarify the specific behavioral mechanisms related to adolescent smoking that will later serve as additional points of emphasis for adolescent smoking prevention and cessation efforts, with relations identified at earlier smoking stages informing prevention efforts, and at later stages, cessation efforts. The use of laboratory procedures also has the added benefit of increased sensitivity to detection of temporary increases in impulsive behavior. Such increases in impulsivity may occur as a result of certain environmental events and may play a determining role at different stages of smoking uptake. For example, pilot data using a laboratory procedure suggest a period of heightened impulsivity associated with adolescents trying cigarettes for the first time (Reynolds et al., 2003). Related to this, a secondary feature of the proposed project will involve exploring relations between self-reported negative life events and impulsive behavior at the different smoking stages. These stress-related variables are already recognized risk factors to smoking initiation among adolescents. This population may be particularly sensitive to negative life events, and these may increase vulnerability to trying cigarettes or the escalation to more frequent use, either in their own right or indirectly through the effects of stress on impulsivity. The possible role of impulsive behavior as a mediator between negative life events and cigarette-smoking status among adolescents will be explored. [unreadable] [unreadable] [unreadable]