Externalizing behavior problems of 124 adolescents were assessed across Grades7–11. In Grade 9, participants were also assessed across social-cognitive domains afterimagining themselves as the object of provocations portrayed in six videotaped vignettes.Participants responded to vignette-based questions representing multiple processes of theresponse decision step of social information processing. Phase 1 of our investigation supported atwo-factor model of the response evaluation process of response decision (response valuation andoutcome expectancy). Phase 2 showed significant relations between the set of these responsedecision processes, as well as response selection, measured in Grade 9 and (a) externalizingbehavior in Grade 9 and (b) externalizing behavior in Grades 10–11, even after controllingexternalizing behavior in Grades 7–8. These findings suggest that on-line behavioraljudgments about aggression play a crucial role in the maintenance and growth of aggressiveresponse tendencies in adolescence.