Social influence in the crowd: Attitudinal and behavioural effects of de‐individuation in conditions of high and low group salience*

The study described here uses the social identity framework suggested by Tajfel and Turner to argue that de‐individuation works by altering the salience of personal vs. social identity. Seventy students from science and 38 students from social science faculties were shown a film presenting arguments for and against vivisection, at the end of which they were told that science students had a pro‐ and social science students an anti‐vivisection norm. Subjects were then told that they were being examined either as members of their faculty group or as individual students. They were either de‐individuated or individuated. They were required to fill in an attitude questionnaire and to complete three quasi‐behavioural measures. It was predicted that the group condition should increase salience of social identity and adherence to the group norm. It was also predicted that de‐individuation in the group condition would further increase salience and hence normative behaviour, while in the individual condition de‐individuation would decrease salience and hence normative behaviour. The first prediction was upheld on all the measures, and the second was partially confirmed.