A study was conducted with 128 female college students to test the hypothesis that when observers feel vulnerable to rape, they are more likely to blame a rape victim3 and are less willing to offer social support. Similarity and empathy were expected to moderate the effects of perceived vulnerability on blame and predict greater social support. Assumptions about the world were predicted to be associated with greater blame. A multivariate model was tested with structural equation modeling techniques. Perceived vulnerability did not directly or indirectly predict blame. However, similarity directly predicted less blame and indirectly predicted greater social support through associations with blame, perceived vulnerability, and empathy. World assumptions directly predicted greater blame and indirectly predicted less social support through blame. These findings suggest that blame and social support are interrelated processes which are associated with social observers' perceptions of the victim and their basic assumptions about the world.