It was an issue of great personal importance to young men who thought they might be drafted, and possibly killed, in a war they regarded as immoral. Janis and Rausch (1970) tested for selective exposure to propledge and antipledge communications among four different kinds of Yale students: those who immediately refused to sign the , those who refused after some deliberation, those who favored the pledge and said they might sign, and those who had already signed it.
Source: wiktionary