Although self-efficacy is a construct found throughout research literature, little is known about the psychological mechanisms that give rise to perceptions of personal confidence. This situation is changing as a result of the introduction of the knowledge-and-appraisal personality architecture (KAPA; Cervone, 2004), a theory proposed to explain the origins of self-efficacy percepts. In the present study, KAPA's framework was utilized to predict university students' self-efficacy toward 3 physically demanding leisure activities. The results support the theory's validity. Confidence was strongly related to how personal characteristics were thought to influence performance of a leisure activity. Self-efficacy was significantly higher when personal attributes were thought to help with performance vs. when attributes were believed to hinder performance.