Whereas a variety of research has investigated how individual differences moderate attitude change (persuasion) processes, there is a relative dearth of research investigating how such individual differences moderate behavior change (compliance) processes. The current research assessed the extent to which two well-studied personality traits predicted susceptibility to the mindlessness technique (Langer, Blank, & Chanowitz, 1978). After completing need for cognition and self-monitoring scales, participants were asked to make photocopies for the experimenter. At the copy machine, a confederate asked to cut in line, providing no reason, a real reason, or a placebic reason. Results replicated those of Langer et al. (1978): The placebic reason elicited as much compliance as the real reason. Need for cognition did not moderate compliance, and participants high in self-monitoring were less likely to comply across conditions. In addition, participants who refused the request took significantly longer to respond than participants who complied. Our research, therefore, provides insight into a largely neglected field of study: How and when individual differences moderate behavior change processes.