Theories of Collective Behavior

Collective behavior is relatively spontaneous behavior that follows from the formation of a group or crowd of people who react to a common influence in an ambiguous situation. It is a type of social behavior that occurs when people are influenced by others and take action toward a shared goal. This can happen spontaneously or can develop over time. Overall, collective behavior is less structured than what might be considered everyday behavior, such as what happens day-to-day in a workplace, classroom, or public park. In these situations, individuals tend to act according to relatively stable customs and institutional rules and expectations. Such customs, rules, and expectations may fail to function in collective behavior situations. In some situations, such as moral panics (concern or fear that a group or behavior threatens society, related to changing moral standards) or mobs, collective behavior is exhibited by people who are near one another but who may or may not be interacting with each other. Gossip, mass hysteria, and fads exemplify collective behavior by people who are not near one another—who might even be separated by great geographical distances—but share similar beliefs or concerns.

French scholar Gustave Le Bon (1841–1931) developed contagion theory as he studied the history of mobs and rioting of the French Revolution (1787–99). Contagion theory posits that crowds can have an effect on individuals, causing people to develop mob mentality and lose the ability to reason. Caught up in the experience of a crowd, people are more likely to behave emotionally and irrationally. Le Bon's work has been criticized as highly biased, reflecting his low opinion of the revolution and, more generally, his prejudices against the poor and the working class. His contagion theory lost favor in the face of clear findings that collective behavior is often thoughtful and logical, contradicting Le Bon's theory. It is important to note that Le Bon's concept reflects 19th-century beliefs about psychology, framing the effect of crowds on people as "hypnotic." Assumptions that collective behavior is irrational and that crowds can exert a "contagious" influence remain popular. However, in the 21st century, scholars argue that collective behavior is much more rational than the model described by contagion theory.

Emergent norm theory holds that individual members of a crowd or group make their own decisions about behavior and that norms are created through others' acceptance or rejection of these behaviors. According to this theory, people in a crowd or group might not know how to behave initially, and thus they take cues from the behavior of others. This is in part because members sense that traditional norms do not apply in the context of the crowd or other situation of collective behavior. Eventually, through multiple and interweaving series of individual decisions, the crowd or group develops new norms governing behavior. Thus emergent norm theory views collective behavior as generally rational, although it can be relatively unpredictable. Emergent norms can change quickly, responding to circumstances. One reason for this is that new members of a group can easily start new norms. During a political demonstration, for instance, a norm to ignore counterprotesters might emerge. This norm could change with the arrival of new participants to the demonstration, who create a new norm of interacting with counterprotesters. Emergent norm theory would see such a change as due to the decisions of other crowd members to embrace the new norm. However, despite the potential for norms to change quickly, emergent norm theory argues that observable patterns of behavior exist in crowds and other groups and that these patterns can help predict the behavior of individuals.

Convergence theory argues that crowd behavior is a reflection of the beliefs, attitudes, and behaviors that individuals bring to a crowd. While contagion theory and emergent norm theory focus on how crowds affect individuals, convergence theory sees individuals as the key force that affects crowds. This theory proposes that crowds usually form because people who share ideas, viewpoints, and beliefs choose to converge, or come together. Crowd behavior is thus understood as a reflection of the assumptions, goals, and attitudes that most members of the crowd already hold. People who join a crowd may end up engaging in behavior that they would not carry out on their own, such as rioting or committing hate crimes. Convergence theory understands this behavior as based on individuals' beliefs, even if participation in a crowd is what leads some individuals to choose to act in an extreme or unusual fashion.

Value-added theory proposes that collective behavior occurs when several major factors are combined: awareness of an issue, social strain, generalized beliefs, precipitating factors, mobilization, and a lack of social control. Awareness of a social problem or issue is a first step, but value-added theory stresses that other factors must also occur in order to prompt collective behavior. Social strain (or structural strain) refers to tension or anger related to a social problem. Generalized beliefs are shared beliefs about the source of social problems and the best ways to address them. Precipitating factors are events that push people to take action linked to the problems of concern to them. Mobilization occurs when leaders emerge to organize people, by facilitating communication and proposing action. Social control refers to consequences linked to behavior. When people perceive a lack of social control, believing that they will not face negative or harsh consequences, they are willing to take the action they believe the precipitating event calls for. Value-added theory can be used to understand crowd behavior, such as riots, but is also used to analyze why and how broad social movements occur.