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Deindividuation is the “loss of self awareness and of individual accountability in a group”. The theory of deindividuation seeks to explain the violent and impulsive behavior of the individual in large crowds and mobs.
Gustave Le Bon was one of the first psychologists to analyze the behavioral effects of crowds. Le Bon’s book The Crowd (1895) stated that when an individual is placed in a crowd, the unconscious mind of each individual emerges and creates a “collective mind” that is primitive in nature, causing uninhibited behavior.
A couple decades later, the issue of crowd behavior was examined once again and revised. Social psychologists were able to identify and describe antecedent conditions that facilitate deindividuation. Festinger (1952) was the first to propose that anonymity was a key element in the effects of deindividuation. The presence of a large number of people diffuses the responsibility amongst the members of the group, thus reducing the accountability of individuals for their actions. Zimbardo (1969) added to Festinger’s theory and specified other causes of deindividuation. Groups also tend to exhibit high arousal that can have an energizing effect on each person, which in turn causes them to feel more excited. High arousal may produce a sensory overload, forcing the individual to depend on automatic processing to make quick assessments and decisions, which may be inaccurate or impulsive. These effects may also be exacerbated by the use of drugs or alcohol.
When deindividuation occurs, many internal processes occur within the individual. Deiner (1980) suggested that reduced self-awareness was the distinctive characteristic of deindividuation. Attention is focused outward, away from the individual, thus decreasing the salience of personal identity. There is reduced self-observation and self-evaluation, and lessened concern with how others evaluate our behavior. Because the individual disregards societal norms for behavior, internal inhibitions are weakened. The individual lacks emotions associated with guilt, fear, and shame.
The combination of the antecedent conditions and internal states culminates in observable behaviors. People that are in crowd situations act impulsive, irrational, emotional, and antisocial.
Many research experiments have been conducted that demonstrate the process and effects of deindividuation. One of the most famous experiments is the Halloween Study by Diener et al., (1976). In this study, a confederate presented a bowl of candy to trick-or-treaters. When the children would come to the door, the confederate would leave momentarily and tell the kids to only take one piece of candy. The independent variables were if the children came to the door in a group or alone, and if they were forced to make their identity salient or not. Another experimenter observed how many children took more than one piece of candy. The results showed that the children who were alone and identified themselves were the least likely to take more than one piece of candy, whereas the children who were in a group and anonymous were the most likely to take more. This study illustrated how anonymity within in a group contributed to stealing more candy. However, because this experiment was based on naturalistic observation, it was difficult to assess the self-awareness of the children.
Another classic study was conducted by Zimbardo (1969), in which participants came to a lab and administered shocks to a woman, similar to Milgram’s Shock Experiment. The participants were either dressed in large lab coats and hoods to hide their identity or they wore their regular clothing with a name tag. Shocks were administered longer when the participant was anonymous and wore the lab clothing. Once again, we see the role of anonymity in causing antisocial behavior. This experiment had a problem similar to that of the Halloween study in that self-awareness was not directly manipulated.
We can apply the theory of deindividuation to many group situations and events. One example is the violence of the Ku Klux Klan, where members wear white robes to conceal their identity, facilitating harmful and racist behavior. In warfare, armies tend to wear uniforms which conceals one's identity and forms a superficial In-group; also each army dehumanizes its opponents, making it easier to kill the enemy. One can also see the effects of deindividuation at sports games, where high arousal and anonymity create mob riots.