Influence: The Psychology of Persuasion

Content Warning: This chapter contains references to the People’s Temple mass suicide.

Cialdini describes a restaurant in Beijing where, in an effort to boost the sales of certain dishes, they listed them as “most popular.” Sales of these dishes immediately increased. He writes, “Quite simply, the dishes became more popular because of their popularity” (128).

Cialdini attributes this success to a lever of influence called “social proof.” When advertisers say their product is the fastest selling or the most popular, they do not have to explain anything. Popularity speaks for itself. Unfortunately, there are profiteers who claim to have a product that is quite popular when it is not. Cialdini makes a list in the section “People Power” of various aspects of human behavior. In each, he reveals that the most prevalent behavior is led by a small group of initiators and followed by a large group of imitators. These behaviors include morality, criminality, problematic personal behavior, healthy eating, online purchases, bill paying, science-based recommendations, and environmental action. Not only individuals but also organizations tend to follow these leaders.

In “After the Deluge,” Cialdini expresses his favorite example of using social proof to create an unlikely growth in popularity. He describes several religious groups over the centuries that professed radical beliefs of imminent divine occurrences that failed to materialize. Nevertheless, these groups went on to grow in number. He focuses on a group he refers to as “the Guardians,” whom he calls New Age, quasi-Christians based in Chicago in the mid-1950s. Adherents accepted the belief, largely because of the automatic writing of one member, that there would be a great flood that would destroy the city. However, because of the faithfulness of this group, a flying saucer would come and transport them to safety on a certain date and time. When the spaceship did not appear, instead of disbanding, they went out and began to evangelize for the first time. They continued to build the group zealously, seeking social proof since there was no physical proof.

In “Optimizers,” Cialdini lists three conditions necessary for social proof to achieve its most powerful sway: uncertainty, a mass of people acting together, and similarity between the uncertain individuals and the mass. When people are uncertain, they look at the actions, behaviors, and beliefs of others. They adopt and follow what they see as appropriate for themselves. He terms the tendency to see what everybody else is doing when one is uncertain “pluralistic ignorance” (145).

Cialdini writes in “Scientific Summary” that when all doubt is removed about whether something is an emergency, people respond immediately by being helpful. However, when viewers cannot determine if something is an emergency, they tend to look around themselves to see if anybody else recognizes a crisis. In “Devictimizing Yourself,” Cialdini explains the importance of how to let somebody know if you experience a crisis to avoid the possibility that people simply do not respond.

In “The Many: The More We See, the More There Will Be,” Cialdini describes the way that gathering a small group of people and engaging in an activity like looking toward the sky will tend to cause others around to join the group. He refers back to a phenomenon called “claquing” that began in 19th-century Paris when opera goers wanted to produce applause during performances. This activity of claquing continues in current political campaigns since politicians load debate audiences with people who will react in prescribed ways to support a given candidate.

Writing in “Why Does ‘The Many’ Work So Well?” Cialdini refers to a shopping center food court that managed to diminish the crush of lunchtime visitors by showing a poster with many people eating an early lunch. In “Validity,” he explains that popular decisions are self-validating, as when a man in London in the 18th century predicted a great earthquake would devastate the city. A few people believed him, yet when others saw the believers moving out of the city, the numbers grew until there was panic as everyone tried to leave. The predicted day passed without any quake. Citizens were furious at the prophet rather than at themselves for accepting the social proof.

Cialdini adds another element to the potential usefulness of social proof by saying that what must happen to build popularity in this manner is “Feasibility.” He writes, “[I]f lots can do it, it must not be difficult to pull off” (160). Regarding “Social Acceptance,” Cialdini writes that it is emotionally much easier to adopt the attitude of the group. Standing apart from the group creates emotional stress many cannot bear.

In addition to uncertainty and the great mass of people moving in one direction, the other contributing factor to social proof’s efficacy is “Similarity” among participants. He refers to this as “peer-suasion.” People feel they are part of the group or want to be part of the group. He writes that it is possible to get homeowners to react similarly by saying that other homeowners in similar homes conduct themselves in particular ways.

Cialdini explores the dark side of this aspect of human behavior in the section “Monkey See, Monkey Do...Monkey Die.” He talks about suicidal behavior and even homicidal behavior stemming from the imitation of others. He refers to several scientific studies revealing that imitators will take their own lives and the lives of others in proximity to the suicidal, homicidal acts of others.

Following this, he focuses on the terrible experience of “Monkey Island,” which deals with the People’s Temple mass suicide in 1977. The Reverend Jim Jones, who faced criminal investigation, told all his followers to drink strawberry-flavored poison. As a result, 909 people died with only a few congregants resisting. Cialdini says that Jones recognized he needed a few individuals who would mindlessly follow his lead and that, through social proof, the others would follow. He writes, “[T]he most influential leaders are those who know how to arrange group conditions to allow the principle of social proof to work in their favor” (183).

In the next section, “The Big Mistake,” he describes an environmental crisis at the petrified forest where visitors were stealing small pieces of fossilized wood. When park officials tried to stem the practice by posting information about what was happening, the theft of petrified wood only increased. Cialdini pointed out that they were inspiring larceny by saying how common it was. He advised them to change their sign to focus on the many honorable people who did not steal souvenirs from the park. The number of thefts accordingly decreased. In “A Social Proof Shortcut (to the Future),” he deals with a second social proof mistake that has to do with what if there is no social proof that one can point to. He relates that one can assume that there is going to be a trend and market that as a way of promoting potential social proof. He calls this a “future social proof.”

Writing about “Defense” against faulty social “proof-suasion,” Cialdini says that it is important to retain the shortcut of social proof to point us in the direction everyone else is moving. One must also recognize that the decisions of a group are not always correct and sometimes groups can be misled on purpose. He says that the best defense against social proof errors is knowing “when the data are in error” (191). He gives examples of when this can happen in “Sabotage,” when there is a direct attempt to persuade others to believe in social proof that is non-existent. He also says there are those occasions, in “Looking Up,” when an innocent mistake produces a snowball effect, leading people away from the reality of the situation.