It is almost a truism that the groups we belong to play an important role in shaping our beliefs and attitudes. And yet, for most of their short history, the study of persuasion and attitude change developed almost independently from research on social or group in¯uence. The two ®elds used different stimulus materials and developed different theoretical perspectives. Research on persuasion studied the impact of complex messages on individual attitudes. In contrast, studies of majority/minority in¯uence focused mainly on the effect that knowledge of the judgements of other group members had on an individual member's judgement of simple physical stimuli (e.g., Asch, 1956; Moscovici, 1980; Moscovici & Faucheux, 1972; Sherif, 1936). Only during the last few decades has there been a convergence between the two research traditions, with students of group in¯uence increasingly using complex messages in their research (e.g., Baker & Petty, 1994; Maass & Clark, 1983; Mackie, 1987).