Contagion Theory
Le Bon's Contagion Theory: An Explanation of Psychology of the Individual in Crowds
Gustave Le Bon (1841-1931), a French social psychologist, in his classic analysis of mobs and crowd behavior he published in 1895, titled The Crowd: A Study of the Popular Mind, formulated the contagion theory, which proposes that people are more likely to engage in antisocial behavior in a crowd because they are anonymous and feel invulnerable.
The Contagion theory proposes that crowds exert a hypnotic influence on their members. The hypnotic influence, combined with the anonymity of belonging to a large group of people, results in irrational, emotionally charged behavior. Or, as the name implies, the frenzy of the crowd is somehow contagious, like a disease, and the contagion feeds upon itself, growing with time.
Contagion theory focuses on the social-psychological aspects of collective behavior and attempts to explain how moods, attitudes, and behavior are communicated rapidly and why they are accepted by others (Turner and Killian, 1993).
Le Bon (1960/1895) suggested that a crowd takes on a life of its own that is larger than the beliefs or actions of any one person. Because of its anonymity, the crowd transforms individuals from rational beings into a single organism with a collective mind. He concluded that a crowd of people could, in certain instances, become a unified entity that acted as if guided by a single collective mind. Le Bon wrote,
- Whoever be the individuals that compose it, however like or unlike be their mode of life, their occupations, their character, or their intelligence, the fact that they have been transformed into a crowd puts them in possession of a sort of collective mind which makes them feel, think, and act in a manner quite different from that in which each individual of them would feel, think, and act were he in a state of isolation. (1895/1960, p. 27)
Le Bon believed that no matter what the individual qualities of the people in the group, the crowd would transform them, changing them from rational, thoughtful individuals into impulsive, unreasonable, and extreme followers. Once people fall under the “law of the mental unity of crowds” (1895/1960, p. 24), they act as the collective mind dictates.
In essence, Le Bon asserted that emotions such as fear and hate are contagious in crowds because people experience a decline in personal responsibility; they will do things as a collectivity that they would never do when acting alone.
Le Bon was a physician, so he viewed the collective mind as a kind of disease that infected one part of the group and then spread throughout the rest of the crowd.
After observing many crowds firsthand, Le Bon concluded that emotions and behaviors could be transmitted from one person to another just as germs can be passed along, and he believed that this process of contagion accounted for the tendency of group members to behave in very similar ways (Wheeler, 1966).
Many of Le Bon’s speculations have been discredited, but he was right about one thing: Contagion is common in groups. People unconsciously mimic each other during everyday social interaction—if one person stands with her arms crossed over her chest, before long several of the others in the group will also cross their arms (Chatrand & Bargh, 1999).
Contagion is the spread of behaviors, attitudes, and affect through crowds and other types of social aggregations from one member to another (see hysterical contagion). In a crowd every sentiment and act is contagious. — Le Bon (1895/1960, p. 50) |

One person laughing in an audience will stimulate laughter in others. Questions and answer sessions after a lecture usually begin very slowly, but they soon snowball as more and more questioners begin raising their hands. Individuals’ emotions tend to converge over time when they interact frequently in groups (Anderson, Keltner, & Oliver, 2003).
Mimicry of others is so basic a process that researchers believe that so-called mirror neurons Opens in new window are active when others’ actions are observed, and that these neurons play a role in producing the identical behavior in the observer (Semin, 2007). Mimicry explains why members of collectives act as if they are guided by a single mind: As one person imitates the next, the collective begins to act in a uniform manners.
Le Bon believed that such contagion processes reflected the heightened suggestibility of crowd members, but other processes may be at work as well. Because many crowd settings are ambiguous, social comparison processes may prompt members to rely heavily on other members’ reactions when they interpret the situation (Singer et al., 1982).
Contagion may also arise in crowds through imitation, social facilitation, or conformity (Chapman, 1973; Freedman & Perlick, 1979). Herbert Blumer combined these various processes when he argued that contagion involves circular reactions rather than interpretive reactions (Blumer, 1946, 1951, 1957).
During interpretive interactions, group members carefully reflect on the meaning of others’ behavior and try to formulate valid interpretations before making any kind of comment or embarking on a line of action.
During circular reactions, however, the group’s members fail to examine the meaning of others’ actions cautiously and carefully and, therefore, tend to misunderstand the situation. When they act on the basis of such misunderstandings, the others in the group also begin to interpret the situation incorrectly, and a circular process is thus initiated that eventually culminates in full-blown behavioral contagion.
Criticisms of Contagion Theory
There are several inconsistencies with Le Bon’s theory. First, contagion theory presents members of crowds as irrational. Much crowd behavior, however, is actually the result of rational fear (e.g., being trapped in a burning theater) or a rational sense of injustice (e.g., the Cincinnati race riots).
Second, crowd behavior is often instigated by and guided by individuals. That the crowd seems to take on a life of its own is certainly true, but the influence of the individual should not be overlooked.
It is worth noting that Le Bon’s book is compiled based on the perspective of a frightened aristocrat. He interprets the crowd episodes of the French Revolution as irrational reversions to animal emotion, which he sees as characteristic of crowds in general. Blumer sees crowds as emotional, but as capable of any emotion, not only the negative ones of anger and fear.
