An attentional model of fear-based behavior is proposed and a study that tested the model is reported. It was predicted that among subjects with moderate fear of snakes, heightened self-attention during an approach attempt would cause increased awareness of existing anxiety, followed by one of two courses of events: Subjects who believed that they could do the behavior in spite of their fear were expected to redirect their attention to the behavior--goal comparison and exhibit no behavioral deficit. Subjects who doubted their ability to do the behavior were expected to divert their attention from the behavior--goal comparison and to withdraw behaviorally from the approach attempt. The results of the study support this reasoning. Discussion centers on relationships between the proposed model and previous theory.