Behavioral contagion
Behavioral contagion is a form of social contagion involving the spread of behavior through a group. It refers to the propensity for a person to copy a certain behavior of others who are either in the vicinity, or whom they have been exposed to. The term was originally used by Gustave Le Bon in his 1895 work The Crowd: A Study of the Popular Mind to explain undesirable aspects of behavior of people in crowds. In the digital age, behavioral contagion is also concerned with the spread of online behavior and information. A variety of behavioral contagion mechanisms were incorporated in models of collective human behavior.
Behavioral contagion has been attributed to a variety of different factors. Often it is distinguished from collective behavior that arises from a direct attempt at social influence. A prominent theory involves the reduction of restraints, put forth by Fritz Redl in 1949 and analyzed in depth by Ladd Wheeler in 1966. Social psychologists acknowledge a number of other factors, which influence the likelihood of behavioral contagion occurring, such as deindividuation and the emergence of social norms. In 1980, Freedman et al. have focused on the effects of physical factors on contagion, in particular, density and number.
J. O. Ogunlade the observer and the model share a similar situation or mood the model's behavior encourages the observer to review his condition and to change it; c) the model's behavior would assist the observer to resolve a conflict by reducing restraints, if copied; and d) the model is assumed to be a positive reference individual.
Types of contagion
Social contagion can occur through threshold models that assume that an individual needs to be convinced by a fraction of their social contacts above a given threshold to adopt a novel behaviour. Therefore, the number of exposures will not increase chances of contagion unless the number of source exposures pass a certain threshold. The threshold value can divide contagion processes to two types: 1) Simple contagion and 2) Complex contagion.Simple contagion
The individual needs only one person displaying the novel behaviour to copy. For instance, cars travel in groups on a two-lane highway since the car in each cluster travels at a slower speed than the car behind it. This relative speed spreads through other cars who slow down to match the speed of the car in front.Complex contagion
The individual needs to be in contact with two or more sources exhibiting the novel behaviour. This is when copying behaviours needs reinforcement or encouragement from multiple sources. Multiple sources, especially close friends, can make imitation legitimate, credible and worthwhile due to collective effort put in. Examples of complex contagions include a New York University School of Business study in California which found that households were more likely to install solar panels in neighborhoods that already had them, and that the rate of installation increases with more and more installations, creating a chain reaction that added up to a significant increase in solar adoption. Other examples can be copying risky behaviour or joining social movements and riots.Factors
Strength of ties
Social contagion in simple contagion models occurs most effectively through 'weak' and 'long' ties between social contacts. A 'weak' tie between two people means they do not interact as frequently and do not influence each other as close friends. However, a relationally 'weak' tie is structurally strong if it is 'long' because it connects socially distant people, showing greater outreach than a relationally 'strong' tie. These 'long' ties allow the flow of new information increasing rate of transmission that relationally strong ties cannot do. Even though close friends can strongly influence each other, they will not help each other learn about new opportunities, ideas or behaviours in socially distant settings if they all know the same things. Few 'weak' and 'long' ties can help spread information quickly between two socially distant strong networks of people. 'Strong' ties within those networks can help spread information amongst the peers.On the other hand, complex social contagion processes require multiple sources of influence. This is not possible with few 'weak' ties: they need to be long and multiple in number to increase the probability of imitation between socially distant networks.
Structural equivalence
However, social contagion can also occur in the absence of any ties during competition. This happens when two people are structurally equivalent i.e., they occupy the same position in a social network and have the same pattern of relationships with the same people. For instance, two students publishing the same kind of research under the same professor are structurally equivalent. The more similar their relations are with other people i.e. the more substitutable they are with one another, the more they will copy what the other is doing, if it makes them look better, to stay ahead of competition.Reduction of restraints
Behavioral contagion is a result of the reduction of fear or restraints – aspects of a group or situation which prevent certain behaviors from being performed. Restraints are typically group-derived, meaning that the "observer", the individual wishing to perform a certain behavior, is constrained by the fear of rejection by the group, who would view this behavior as a "lack of impulse control".An individual wants to perform some behavior, but that behavior would violate the unspoken and accepted rules of the group or situation they are in; these rules are the restraints preventing the observer from performing that action. Once the restraints are broken or reduced the observer is then "free" to perform the behavior; this is achieved by the "intervention" of the model. The model is another individual, in the same group or situation as the observer, who performs the behavior which the observer wished to perform. Stephenson and Fielding describe this effect as " one member of a gathering has performed a commonly desired action, the payoffs for similar action or nonaction are materially altered.... initiator, by his action, establishes an inequitable advantage over the other members of the gathering which they may proceed to nullify by following his example."
Density and number
Density refers to the amount of space available to a person – high density meaning there is less space per person – and number refers to the size of the group. Freedman put forth the intensification theory, which posits that high density makes the other people in a group more salient features of the environment, this magnifying the individual's reaction to them. Research has shown that high density does in fact increase the likelihood of contagion. Number also has an effect on contagion, but to a lesser degree than density.Local trend imitation
However, the probability that an individual will copy a behaviour can also decrease with higher density and number of neighbours. For instance, a person might praise and go to a restaurant with good food based on others’ recommendations but avoid it when it becomes over-crowded. This depicts the local trend imitation phenomenon i.e. the adoption probability first increases with increase in number of adopted neighbours and then decreases.Identity of the model
Stephenson and Fielding state that the identity of the model is a factor that influences contagion. Depending on the behavior, sex of the model may be a factor in the contagion of that behavior being performed by other individuals – particularly in instances of adult models performing aggressive behavior in the presence of children-observers . In this particular series of experiments – Albert Bandura's Bobo doll experiments from 1961 and 1963 – where the behavior of children was studied after the children watched an adult model punching a bobo doll and the model received a reward, a punishment, or there were no consequences, the analyses revealed that the male model influenced the participants' behavior to a greater extent than did the female model; this was true for both the aggressive and the nonaggressive male models.Dominant leaders
Aggressive behaviour or using coercion, fear or intimidation to imitate a behaviour is known as dominance. People are likely to follow dominant leaders to avoid the cost of punishment. However, such behaviour is more influential amongst children rather than adults: coercive children are thought to be more likeable whereas coercive adults are less likeable and, hence, influential.Prestigious influencers
While dominant behaviour is displayed in the animal kingdom as well, prestigious behaviour is unique to humans. Humans understand the intentions behind someone's actions rather than just being able to copy their movements precisely. This is important since it is easier to learn from the best models rather than learning by ourselves: We might know which behaviour contributes to someone's success at mastering a skill. Hence, we look to see who everyone else is copying i.e. we tend to copy prestigious individuals. Prestigious people enjoy a high degree of influence and respect and are generally the people with the most information.Ordinary people
A study done on the rate of information transmission via retweets on Twitter found that popular people i.e. people with a large following, are 'inefficient hubs' in spreading concepts. The more followers someone has, the more overloaded they are with information and lower the chances that they will retweet a particular message due to limited attention. Hence, rate of social contagion slows down.Rather, social contagion can amplify amongst 'ordinary' users with low following if they are closely connected in a peer network. People are more likely to retweet messages by close friends to facilitate social bonding. Peers also have higher similar interests and are more influenced by each other than an 'ordinary' and 'popular' user who do not have mutual ties. Hence, social contagion can occur efficiently amongst tight community structures, in the absence of prestigious and dominant leaders.