Crowd psychology

thumb|[[Time-lapse video of a crowd at Saint-Lazare metro station in Paris during rush hour. Filmed in November 2025.]]

thumb|upright=1.2|The psychology of a crowd is a collective behaviour realised by the individuals within it.

Crowd psychology (or mob psychology) is a subfield of social psychology which examines how the psychology of a group of people differs from the psychology of any one person within the group. The study of crowd psychology looks into the actions and thought processes of both the individual members of the crowd and of the crowd as a collective social entity. The behavior of a crowd is much influenced by deindividuation (seen as a person's loss of responsibility) and by the person's impression of the universality of behavior, both of which conditions increase in magnitude with size of the crowd. Notable theorists in crowd psychology include Gustave Le Bon (1841-1931), Gabriel Tarde (1843-1904), and Sigmund Freud (1856-1939). Many of these theories are today tested or used to simulate crowd behaviors in normal or emergency situations. One of the main focuses in these simulation works aims to prevent crowd crushes and stampedes.

Origins

According to his biological theory of criminology, which suggests that criminality is inherited and that someone "born criminal" could be identified by the way they look, Enrico Ferri expressed his view of crime as a degeneration more profound than insanity, for in most insane persons the primitive moral sense survives the wreck of their intelligence. Along similar lines were the remarks of Benedickt, Sergi and Marro. A response from the French, who put forward an environmental theory of human psychology, M. Anguilli called attention to the importance of the influence of the social environment upon crime. Professor Alexandre Lacassagne thought that the atavistic and degenerative theories as held by the Italian school were exaggerations and false interpretations of the facts, and that the important factor was the social environment."

In Paris during 10–17 August 1889, the Italian school received a stronger rebuke of their biological theories during the 2nd International Congress of Criminal Anthropology. A radical divergence in the views between the Italian and the French schools was reflected in the proceedings.

: "Professor Lombroso laid stress upon epilepsy in connection with his theory of the 'born criminal'. Professor Léonce Pierre Manouvrier characterized Lombroso's theory as nothing but the exploded science of phrenology. The anomalies observed by Lombroso were met with in honest men as well as criminals, Manouvrier claimed, and there is no physical difference between them. Baron Raffaele Garofalo, Drill, Alexandre Lacassagne and Benedikt opposed Lombroso's theories in whole or in part. Pugliese found the cause of crime in the failure of the criminal to adapt himself to his social surroundings, and Benedikt, with whom Tarde agreed, held that physical defects were not marks of the criminal qua criminal." It is in this context that you have a debate between Scipio Sighele, an Italian lawyer and Gabriel Tarde, a French magistrate on how to determine criminal responsibility in the crowd and hence who to arrest. (Sighele, 1892; Tarde, 1890, 1892, 1901) The attitude towards crowds underwent an adjustment with the publication of Hippolyte Taine's six-volume The Origins of Contemporary France (1875). In particular Taine's work helped to change the opinions of his contemporaries on the actions taken by the crowds during the 1789 Revolution. Many Europeans held him in great esteem. While it is difficult to directly link his works to crowd behavior, it may be said that his thoughts stimulated further study of crowd behavior. However, it was not until the latter half of the 19th century that scientific interest in the field gained momentum. French physician and anthropologist Gustave Le Bon became its most-influential theorist.

Types of crowds

There is limited research into the types of crowd and crowd membership and there is no consensus as to the classification of types of crowds. Two recent scholars, Momboisse (1967) and Berlonghi (1995) focused upon purpose of existence to differentiate among crowds. Momboisse developed a system of four types: casual, conventional, expressive, and aggressive. Berlonghi classified crowds as spectator, demonstrator, or escaping, to correlate to the purpose for gathering.

Another approach to classifying crowds is sociologist Herbert Blumer's system of emotional intensity. He distinguishes four types of crowds: casual, conventional, expressive, and active. A group of people who just so happen to be at the same location at the same time is known as a casual crowd. This kind of mob lacks any true identity, long-term goal, or shared connection. A group of individuals who come together for a particular reason is known as a conventional crowd. They could be going to a theater, concert, movie, or lecture. According to Erich Goode, conventional crowds behave in a very conventional and hence somewhat structured manner; as their name suggests, they do not truly act out collective behavior. Escapist mobs are characterized by a large number of people trying to get out of a dangerous situation like the November 2021 Astroworld Festival. Incidents involving crowds are often reported by media as the results of "panic", but some experts have criticized the media's implication that panic is a main cause of crowd disasters, noting that actual panic is relatively rare in fire situations, and that the major factors in dangerous crowd incidents are infrastructure design, crowd density and breakdowns in communication. Acquisitive mobs occur when large numbers of people are fighting for limited resources. An expressive mob is any other large group of people gathering for an active purpose. Civil disobedience, rock concerts, and religious revivals all fall under this category. During submergence, the individuals in the crowd lose their sense of individual self and personal responsibility. This is quite heavily induced by the anonymity of the crowd.

Le Bon's idea that crowds foster anonymity and generate emotion has been contested by some critics. Clark McPhail points out studies which show that "the madding crowd" does not take on a life of its own, apart from the thoughts and intentions of members. Norris Johnson, after investigating a panic at a 1979 The Who concert concluded that the crowd was composed of many small groups of people mostly trying to help each other. Additionally, Le Bon's theory ignores the socio-cultural context of the crowd, which some theorists argue can disempower social change.</blockquote>

Deindividuation theory

Deindividuation theory is largely based on the ideas of Gustave Le Bon Zimbardo's Stanford Prison Experiment has been presented as a strong argument for the power of deindividuation, Further experimentation has had mixed results when it comes to aggressive behaviors, and has instead shown that the normative expectations surrounding the situations of deindividuation influence behavior (i.e. if one is deindividuated as a KKK member, aggression increases, but if it is as a nurse, aggression does not increase). holds that crowd behavior is not a product of the crowd, but rather the crowd is a product of the coming together of like-minded individuals. Convergence theory holds that crowds form from people of similar dispositions, whose actions are then reinforced and intensified by the crowd. Crowd members are further convinced by the universality phenomenon, described by Allport as the persuasive tendency of the idea that if everyone in the mob is acting in such-and-such a way, then it cannot be wrong. social identity theory, which aimed to explain intergroup behavior. A core idea of the theory is that, in addition to personal identities, individuals possess multiple social identities derived from their group memberships. These social identities significantly influence thought processes, emotions, and behaviours. The theory was later expanded into self-categorization theory (Turner et al., 1987), which offers a more detailed understanding of the processes through which groups form. According to this theory, the basis of identities is categorization of oneself and others; different identities can become prominent depending on the group context.

The main idea behind the social identity approach is that people have different social identities, and each one influences how they behave. This idea was central to Reicher's (1984, 1987) model of crowd behaviour, developed from his study of the 1980 St Pauls riot. Unlike earlier theories, like Le Bon's, which claimed people lose their sense of self in a crowd, Reicher argued that people don't lose who their sense of self. Instead, they shift from thinking as individuals to thinking as part of a group. This means their behaviour is not out of control, but guided by the group's shared beliefs about what's appropriate. In the St Pauls riot, the crowd didn't act randomly, their actions reflected a shared group identity and clear sense of purpose.

Reicher (2012) unified earlier and newer research on social identity and crowd behaviour through a framework called the "three transformations," which helps explain many key theories and findings in this area.

The first transformation is cognitive. It refers to the shift from seeing oneself as an individual to identifying as part of a group. This shift leads people to adopt the group's norms, values, and goals as their own. When group identity is salient, individuals tend to view others in terms of group membership, respond more to group-consistent messages, and even experience discomfort more positively when it affirms group identity.

The second transformation is relational. It occurs when people not only identify with a group but also recognize that others present share the same identity. This shared identity leads to greater trust, intimacy, cooperation, and coordination. It also forms the basis for distinguishing between physical crowds people and psychological crowds, where shared identity enables spontaneous collective behavior.

The third transformation is affective. As a result of shared identity and support, people feel empowered to express their group identity in ways they usually cannot. This process, known as collective self-objectification, creates a strong sense of emotional positivity and fulfilment within the crowd experience.

While the three transformations framework focuses on internal crowd dynamics, the social identity approach also emphasizes intergroup relations, particularly between crowds and external groups like the police (Reicher, 1984, 1987). Reicher's original model evolved into the Elaborated Social Identity Model (ESIM), which explains how conflict in crowd events arises through identity change (Drury & Reicher, 2000; Reicher, 1996; Stott & Reicher, 1998).

According to ESIM, two main conditions contribute to the development and escalation of conflict between a crowd and another group, such as the police. First, there is a clash in how each group categorizes the behaviour at the event. For example, crowd members may see their actions as a legitimate protest, while police may interpret them as a threat to public order. Second, there is an imbalance of power, with the police having the ability to enforce their definition of what behavior is acceptable, often through physical control or dispersal.

When police action is seen by the crowd as illegitimate - such as being perceived as an attack on their right to protest - it can justify resistance. If that action is also viewed as indiscriminate, affecting everyone in the crowd regardless of individual behaviour, it can create a sense of shared fate. This shared experience can lead to the formation of a common identity within an otherwise diverse crowd, overriding internal differences and enhancing.

As this new collective identity forms, it brings a sense of unity, enhanced expectations of support for ingroup-normative actions, and legitimacy for resisting the outgroup (in this case, the police).

The social identity approach to the crowd was extended to explain behaviour in mass emergencies. This was often found to involve cooperation amongst strangers, and research suggested that this spontaneous coordination reflected the emergence in the crisis of a new shared social identity (Drury, 2018). One of the most notable developments in crowd behaviour research over the past 20 years has been the application of the social identity approach to everyday, non-crisis crowd settings, including religious mass gatherings, music events, and pedestrian flow (Drury, 2025).

References

External links

Dr. J. P van de Sande, On Crowds
"Crowd Disasters" by Prof. Dr. G. Keith Still (archived 20 April 2012)
Understanding crowd behaviours – gov.uk