Both Catholic and Protestant respondents watched newsreel footage depicting scenes of in-group and out-group violence: one showed a Protestant attack on mourners at a Catholic attack on a car containing two plain clothes soldiers at a Catholic funeral. A free response format was used to classify subjects' explanations into internal and external attributions. Strong support emerged for Pettigrew's hypothesis. A comparison of Protestant explanations for Protestant violence with Protestant explanations for Catholic violence revealed that the way in which members of the Protestant group attributed in-group and out-group violence differed significantly. Similar results emerged from an analysis comparing Catholic explanations for Catholic violence with Catholic explanations for Protestant violence. The internal attributions, which tended to be relatively negative in tone, demonstrated that Catholics and Protestants were between two-and-a-half to four times more likely to attribute out-group rather than in-group violence to internal causes. 1 table and 23 references