The purpose of this paper is to analyze and synthesize what has been reported from the scientific and professional literature about the “psychology of terrorism.” This focus is not intended to suggest that the scientific discipline of psychology provides the only, or even necessarily the best, analytic framework for understanding terrorism. Like all approaches to understanding or explaining human behavior, a psychological approach has advantages and limitations. Nevertheless, as psychology is regarded as “the science of human behavior,” it seems a reasonable, and potentially productive, line of inquiry.