About Deindividuation Theory, a social psychological account of the individual in the crowd and an attempt to explain anti-normative collective action

Deindividuation theory is a social psychological account of the individual in the crowd. Deindividuation is a psychological state of decreased self-evaluation, causing anti-normative and disinhibited behavior. The impact of deindividuation theory in science and society (especially 20th century politics) make it one of social science's more influential contributions. Deindividuation theory is rooted in some of the earliest social psychological theorizing, more than a century ago. It seeks to explain the apparent transformation of rational individuals into an unruly group or crowd. It posits that the group provides an environment in which the individual --submerged and anonymous -- suffers from a loss of self-awareness (Zimbardo, 1969). Deindividuation hinders reflection about the consequences of actions, rendering social norms impotent while increasing suggestibility to random outside influences. The theory has been invoked to account for a range of phenomena such as collective behavior, behavior in online groups and in CMC, and the results of the classic Stanford Prison Experience. Despite its status and impact, empirical support for deindividuation theory is minimal. Recently, this lack of support has been attributed to the faulty assumption that crowds cause a loss of self. Instead, it has been proposed that deindividuation marks a transition from individual identity to social dimensions of the self. This transition to a social identity may increase responsiveness to social norms particular to the crowd, instead of decreasing responsiveness to generic social norms, as suggested by deindividuation theory.

According to deindividuation theory, the psychological state of deindividuation is aroused when individuals join crowds or large groups. The state is characterized by diminished awareness of self and individuality. This in turn reduces an individual's self-restraint and normative regulation of behavior. In social psychology, deindividuation is a major theory of group behavior: it provides an explanation of collective behavior of violent crowds, mindless hooligans, and the lynch mob. In addition, deindividuation has been associated with other social phenomena such as genocide, stereotyping, and disinhibition in other settings such as computer-mediated communication. Below, the theoretical evolution of deindividuation is sketched, followed by a brief impression of the empirical support for this theory. Finally, recent research is discussed, which argues for a reconceptualization of deindividuation: It appears deindividuation is not a loss of individual identity, but may be better construed as a transition to a social identity.

Deindividuation theory is rooted in the earliest works of social psychology, in particular Gustave Le Bon's (1895/1995) crowd theory. In his book "The Crowd" Le Bon vividly describes how the individual in the crowd is psychologically transformed. He proposes that the psychological mechanisms of anonymity, suggestibility and contagion transform an assembly into a "psychological crowd." In the crowd the collective mind takes possession of the individual. As a consequence, a crowd member is reduced to an inferior form of evolution: irrational, fickle, and suggestible. The individual submerged in the crowd loses self-control and becomes a mindless puppet, possibly controlled by the crowd's leader, and capable of performing any act, however atrocious or heroic.

Although many have criticized Le Bon's theory and his politics --the two are closely linked--, the influence of "The Crowd" in science and society is difficult to underestimate. The sales of this book are among the highest of scientific texts. In science, his analysis has inspired many theories of collective behavior, for example those of Freud, McDougall, Blumer, and Allport. In society, Le Bon's influence has been remarkably strong and more questionable: His theory informed figures such as Mussolini and Hitler, whose ideologies resonated with Le Bon's emphasis on racial factors (Nye, 1975).

The field of social psychology revived Le Bon's ideas in the 50s. They were couched in more scientific terms as a theory of "deindividuation." Initially, it was argued that deindividuation occurs when individuals in a group are not paid attention to as individuals (Festinger, Pepitone, & Newcomb, 1952). Thus, being unaccountable in a crowd or group has the psychological consequence of reducing inner restraints, and increasing behavior that is usually inhibited. The causes of deindividuation were gradually extended from anonymity in groups to other contextual factors, such as reductions of responsibility, arousal, sensory overload, a lack of contextual structure or predictability, and altered consciousness due to drugs or alcohol (Zimbardo, 1969).

Thus, although Le Bon's ideas were the blueprint for the deindividuation concept, the situations that cause deindividuation were gradually expanded to include other settings than the crowd. Deindividuation theory differs from Le Bon's theory in one further important respect: The consequence of deindividuation is not that the loss of individuality is replaced by a collective mind that guides the individual's actions. Rather the loss of individuality leads to a total loss of control, and releases a person from internalized moral restraints to produce emotional, impulsive, irrational, regressive and intense behavior.

In the 1970s, deindividuation theory became a popular focus of scientific research, encouraged and inspired in part by the collective disorders characteristic of that period. However, the empirical support for deindividuation theory was not especially forthcoming. In particular, there was inconsistent evidence regarding the influence of anonymity in groups, and there was virtually no evidence for the psychological state of deindividuation (Diener, 1980). Indeed, it appeared that this psychological state, which by all accounts appeared to be easily induced, was more elusive than initially conceived.

In order to come to terms with the empirical obstacles, deindividuation theory was gradually modified and specified over the course of the 80s. In particular, the psychological underpinnings of deindividuation have been narrowed down. In the original version of the theory, deindividuation was closely bound up with the lack of accountability that accompanies submergence in the group. Hence, empirically the focus often was on anonymity in the group as the most important factor to produce deindividuation. Contemporary formulations of the theory focus on the psychological process of reduced (private) self-awareness as the defining feature of deindividuation (Diener 1980, Prentice-Dunn and Rogers 1982). Self-awareness entails a person's becoming the object of one's own attention. This attention for (private) aspects of oneself, such as one's attitudes and norms, increases the capacity for self-regulation. Classical and contemporary views agree, however, on the main thrust of the deindividuation hypothesis: The psychological state of deindividuation brings about anti-normative and disinhibited behavior (Postmes & Spears, 1998, for a review).

Several influential studies were conducted to illustrate the force of deindividuation. For example, Zimbardo (1969) reports a study that inspired much subsequent deindividuation research. In one study, participants were rendered anonymous by clothing them in oversized lab coats and hoods, compared with normal clothes and name tags in the control condition. The participants' task was to shock a confederate in a situation similar to the classic Milgram studies on obedience. In a first experiment using groups of female students, Zimbardo demonstrated that anonymous participants shocked longer (and therefore more painfully) than identifiable participants, in confirmation of his theory.

Aware of the limitations of Zimbardo's research in terms of external validity, Edward Diener and colleagues devised more naturalistic contexts in which to test the theory. In some studies, groups of participants were required to "test" a so-called pacifist, trained to remain non-responsive, by hitting the pacifist with foam swords and so forth. The researchers claimed this provided a measure of aggression that was more ecologically valid for crowd behavior. Results were inconsistent, however. In one study, for example, isolated individuals displayed more aggression than groups did (see Postmes & Spears, 1998 for a review).

In another study, Prentice-Dunn and Rogers (1982) induced deindividuation by instructing participants repeatedly to focus attention outward. In addition to attentional focus, participants were seated in a dimly lit room with loud rock music playing, verbal interaction was encouraged and the groups played exciting video games. In contrast, participants in an internal attention focus condition were told not to interact, performed individual tasks and played non-arousing games in a well-lit quiet room. Results showed that when attention was focused outward, higher levels of aggression were obtained.

These examples illustrate that empirical investigations of deindividuation theory resorted to more and more extreme conditions in search of evidence for deindividuation. Although some studies found support for deindividuation theory's propositions, many failed to support it, and many reported contrary results. Even Zimbardo's (1969) original paper reports that a replication of the study mentioned above obtained the exact opposite results.

Thus, evidence for deindividuation theory appears to be mixed. A recent meta-analysis of the deindividuation literature confirms this impression. This study examines 60 tests of deindividuation theory and concludes that there is insufficient support for deindividuation theory (Postmes and Spears 1998). Disinhibition and anti-normative behavior are not more common in large groups and crowded anonymous settings. Moreover, there is no evidence that deindividuation is associated with reduced self-awareness, or even that reduced self-awareness increases disinhibition. Overall, then, deindividuation theory does not receive sufficient empirical support.

One likely reason for the lack of support for the deindividuation concept, is that the theory is based on Le Bon's analysis of the crowd, which is so over-simplified as to be fundamentally flawed. According to Le Bon, collective behavior is always irrational: The individual in the crowd loses cognitive control. Deindividuation theory accepts this notion. For example, Diener argued that crowd members are "similar to the stimulus-response organism of early behaviorism, with reduced conscious mediation" (1980: 230). This negative and disorderly view of collective behavior stands in stark contrast to historical analyses of the crowd, which stress the crowd's capacity for restraint and orderly behavior (e.g., Rudé, 1964). Moreover, these historical analyses accentuate that the crowd often acts on the basis of moral principles and popular consensus (see also Turner & Killian, 1972). Thus, a compelling case can be made that collective behavior is not unrestrained (as argued by deindividuation theory) but rather restrained by normative processes. The implication is that collective behavior is under conscious control, and far from irrational and unrestrained.

In recent social psychological research, a normative analysis of collective behavior is supported. In deindividuation studies, for example, people are more likely to follow local group norms if they are "deindividuated" (Postmes and Spears, 1998). The idea that behavior could be the result of local group norms was considered explicitly by Johnson and Downing (1979) who varied the manipulation of anonymity developed by Zimbardo. Participants were made anonymous by means of mask and overalls reminiscent of the Ku Klux Klan (similar to Zimbardo's uniforms) or by means of nurses' uniforms. Although compared to the control condition participants shocked somewhat more when dressed in the Ku Klux Klan uniforms, they actually shocked less when dressed as nurses. This finding illustrates that groups are sensitive to normative cues associated with the social context.

Researchers working within the framework of social identity theory have attempted to reconceptualize deindividuation in order to account for the crowd's normative regulation. They argue that deindividuating settings do not cause a loss of self, but they shift a person from an individual identity to a collective identity as a member of the group or crowd. For example, being in a demonstration will accentuate the unity of participants if they rally behind their cause --seemingly oblivious to strong divisions and disagreements that may exist between them. This common group membership may become accentuated if an opposing group (such as the police) acts upon the crowd as if it were one, for example by blocking its way or attempts to contain it. The strong adherence to this common group membership, which emerges over the course of such events, explains why normative regulation within the crowd may occur (Reicher, 1987).

In sum, whereas deindividuation theory argues that the crowd causes a loss of identity, reverting the individual to irrationality, it seems more productive to reconceptualize deindividuation as a shift from a personal identity to a social identity, shared by members of the crowd. This may explain the normative restraint within the crowd as observed by historians, as well as the normative restraint observed in experimental studies of deindividuation.

Diener, E. (1980). Deindividuation: The absence of self-awareness and self-regulation in group members. In P. B. Paulus (Ed.), The psychology of group influence (pp. 209-242). Hillsdale, NJ: Lawrence Erlbaum.

Le Bon, G. (1995). The crowd: A study of the popular mind. London: Transaction Publishers. (Original work published in 1895).

Nye, R. A. (1975). The origins of crowd psychology: Gustave Le Bon and the crisis of mass democracy in the third republic. Bervely Hills, CA: Sage.

Postmes, T., & Spears, R. (1998). Deindividuation and anti-normative behavior: A meta-analysis. Psychological Bulletin, 123, 238-259.

Reicher, S. D. (1987). Crowd behaviour as social action. In J. C. Turner, M. A. Hogg, P. J. Oakes, S. D. Reicher, & M. S. Wetherell (Eds.), Rediscovering the social group: A self-categorization theory (pp. 171-202). Oxford, England: Basil Blackwell.

Rudé, G. (1964). The crowd in history: A study of popular disturbances in France and England, 1730-1848. New York: Wiley.

Zimbardo, P. G. (1969). The human choice: Individuation, reason, and order vs. deindividuation, impulse and chaos. In W. J. Arnold & D. Levine (Eds.), Nebraska Symposium on Motivation (Vol. 17, pp. 237-307). Lincoln, NE: University of Nebraska Press.