ABSTRACT
This paper presents a new theory of group processes and illustrates its application to the related problems of social influence and group polarization. The theory is addressed to the nature of the psychological group and the individual-group relationship. What exactly is a psychological group, what are the essential psychological conditions for individuals to perceive themselves, feel and act as a group? This issue has been the central theme in the work of ourselves and colleagues for nearly 10 years. The current version of the theory developed by one of us over this time is termed self-categorization theory (SCT; Turner, 1982, 1984, 1985; Turner, Hogg, Oakes, Reicher & Wetherell, 1987).
