Participation in high-risk behaviors, such as substance use or dangerous driving practices, is widely reported by young adults and college students. Psychosocial theories explain participation in high-risk behaviors by the effects of risk perception on the outcome of behavior. Physiological researchers assert that biological factors (such as the role of the prefrontal cortex) better account for participation in high-risk behaviors based on impulsive decision-making patterns in substance users. The current study explored the relationship between impulsive decision-making and risk perception by assessing the impact of changes in high-risk perceptions on a measure of impulsive decision-making (delay discounting task). A sample of college daily cigarette smokers (n=32) and never-smokers (n=32), participants at particular risk for problems with substance use and other high-risk behaviors, was used. This study demonstrated that an intervention presenting normative information using motivational interviewing techniques significantly changed multiple perceptions and predicted involvement in high-risk behaviors among the entire sample (p < 0.05), as well as the experimental group's performance on the delay discounting task (t(31) = 1.75, p < 0.05). While perceptions of high-risk behaviors and delay discounting task performance changed within this sample, scores on the delay discounting task and scores on a measure of high-risk perceptions did not significantly correlate prior to or following the intervention. Daily smokers and never-smokers did not differ in delay discounting task performance, but daily smokers reported significantly more positive risk perceptions and greater predicted involvement in drug and alcohol use than never smokers. Results suggest that changes in risk perception can influence delay discounting task performance, but smoking status doesn't appear to moderate this association. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]