Deindividuation Theory
Deindividuation Theory: An Explanation of Psychology of the Individual in Crowds
Deindividuation theory is one of the theories of crowd psychology. According to this theory of deindividuation (see Deindividuation Opens in new window), people who join mobs and riots are thought to do so because they can escape the norms and expectations of socially accepted behaviors (Zimbardo 1969).
Deindividuation theory suggests several factors that lead to this phenomenon. We’ll spend the remainder of this entry delving deeper into each, but for now, here they are in order.
- anonymity
- responsibility
- arousal
- new situation
- group membership
- group size
- self-awareness
1. Anonymity
The first, anonymity, often leads people to participate in destructive or violent behaviors with a mob or riot. People who think they won’t be recognized or caught are more likely to join mobs.
Many times people who participate in riots wear nondescript clothing or masks to hide their identity. They are comforted by the fact that others won’t know who they are and can’t report their actions to police or family members. The fact that many people feel uninhibited while wearing Halloween costumes is a testament to how anonymity can affect a person’s choice to participate in certain behaviors.
2. Responsibility
Many people participate in riots because they do not feel responsible for the violent or aggressive behaviors. They see the responsibility for the violence or destruction as being shared with others. In some cases, people deny having any responsibility for their actions, regardless of how destructive or counter these actions are to their everyday behaviors.
People are more at ease giving up responsibility because they feel that the norms of the situation allow them to behave in ways that they might normally not—it’s justification for participating in the mob or riot.
3. Arousal
Deindividuation theory also recognizes the fact that heightened or altered states of arousal influence a person’s choice to join a mob or riot. Alcohol, drugs, feelings of euphoria, and feelings of invulnerability contribute to deindividuation.
In essence, these states of arousal help to mask feelings, attitudes, and beliefs that might preclude someone from destructive or violent behaviors. Other examples of heightened arousal in recreation, leisure, and experiential education include loyalty to sports teams; a rush from completing a race, event, or competition; or feelings induced by listening to music concerts.
4. New situations
Unique situations also contribute to feelings of deindividuation Opens in new window. People with no experience in a certain context must rely on others for cues on how to behave. If the experienced individuals tend toward behaviors associated with mobs and riots, these actions are deemed acceptable, and inexperienced people will assume these actions are the norm. In new situations, people might not know each other, so conditions of anonymity are more likely to exist.
5. Group membership
Group membership also influences individual behavior. Individuals by themselves cannot be deindividualized; it is affiliation with others that allows people to blend in with the group and become anonymous. People are most likely to exhibit mob and riot behaviors with others because they can hide in the pack, which is impossible in smaller groups or as an individual.

6. Group size
Participation in riots and mobs is also influenced by the size of the group. The larger the mob or riot, the more likely people are to participate. A large group allows people to maintain anonymity to a greater extent than smaller groups do.
7. Self-Awareness
A final component of deindividuation theory is self-awareness. People who lose self-awareness through lack of concern about what others think, feelings of group unity, performance of unrestrained tasks, and loss of sense of time are more likely to participate in mobs and riots.
There are many explanations for why people behave the way they do in crowds. Sometimes crowds turn ugly and mobs form or riots break out. Although not everyone in a crowd will be impelled to join in violent or destructive behaviors, they are part of a socially constructed experience that affects them and that they in turn affect. Even if someone is not participating in destructive actions, the mere presence of that person signifies support to others.
As the size of a mob or riot grows, conditions become more conducive for anonymity, false consensus effects, and feelings of deindividuation.
As the mob or riot takes on a life of its own, participants are more likely to assume that the behaviors exhibited around them are normal and use that as tacit support for their own behaviors. Awareness of the psychological factors that influence individuals in crowds, mobs, and riots can assist recreation, leisure, and experiential educators in planning for and dealing with situations that may arise in their programs or activities.
