A computer-mediated communication system (CMCS) was used to explore the effects of de-individuation on group polarization. Reicher (1984) argued that de-individuating members of a group should increase the salience of group identity and hence normative behaviour, while de-individuating subjects treated as individuals should have the reverse effect.
We extended this idea to the group-polarization paradigm and in addition independently manipulated group salience and de-individuation, which were confounded factors in Reicher's study. It was reasoned that the visual anonymity created by isolating discussants in separate rooms would be de-individuating compared to seating them together in the same room. At the same time either subjects' group or individual identity was made salient. A computer-mediated communication system provided text-based communication for discussants in all four conditions.
Assuming that group polarization reflects conformity to a group norm (Turner et al., 1987), we predicted an interaction between the de-individuation and group salience factors such that greatest polarization in the direction of a pre-established group norm would be obtained in the de-individuatedÐgroup condition, and least in the de-individuatedÐindividual condition. This prediction was confirmed. Explanations of the findings in terms of Reicher's earlier study and in terms of self-attention processes are considered within the general framework of social identity theory. Finally, the relevance of this research to the realm of human communication via computer networks is evaluated.
