Social Identity Model of Deindividuation Effects

The social identity model of deindividuation effects (SIDE model) explains how group behavior is affected by anonymity and identifiability. There [Page 794]are many social situations in which people interact in relatively anonymous ways. In social interactions on the Internet, for example, people often use pseudonyms or avatars (pictures) to identify themselves, and even e-mail addresses do not typically provide much information about senders. Another example is the anonymity people experience when they are in a crowd. An important question, therefore, is how anonymity affects people's behavior.

SIDE was developed as an alternative to deindividuation theory. Deindividuation theory suggests that anonymity leads to a loss of self-awareness, and this loss leads to a rise in antinormative behavior. But deindividuation research shows contradictory results: Anonymity in groups often leads to more normative behavior. SIDE suggests this is because anonymity makes people self-define themselves less as persons but more as members of the social group to which they belong. This increased salience of social group membership (or social identity) leads to increased adherence to the norms of the group.

Today, SIDE is used to explain the effects of anonymity and social isolation in various settings, and an extensive body of research has examined its propositions. Taken as a whole, this research demonstrates that anonymity and identifiability have profound consequences for intergroup relations, group processes, and individual self-definition. Research on SIDE has particularly focused on crowds and collective action, online teams, electronic relationships and virtual communities, and, recently, on social effects of surveillance (e.g., by means of cameras or electronic tagging). This entry first reviews the historical and scientific background of the SIDE model and then explains the model in some detail.