Influence: The Psychology of Persuasion

by Robert B. Cialdini

have uncovered a number of mental shortcuts we employ in making our everyday judgments. Termed judgmental heuristics, these shortcuts operate in much the same fashion as the expensive = good rule, allowing for simplified thinking that works well most of the time but leaves us open to occasional, costly mistakes.

We resist the seductive luxury of registering and reacting to just a single (trigger) feature of the available information when an issue is important to us.

Ethologists, researchers who study animal behavior in the natural environment, have noticed that among many animal species, behavior often occurs in rigid and mechanical patterns. Called fixed-action patterns, these mechanical sequences are noteworthy in their similarity to certain automatic (click, run) responses by humans. For both humans and subhumans, the automatic-behavior patterns tend to be triggered by a single feature of the relevant information in the situation. This single feature, or trigger feature, can often prove valuable by allowing an individual to decide on a correct course of action without having to analyze carefully and completely each of the other pieces of information in the situation. The advantage of such shortcut responding lies in its efficiency and economy; by reacting automatically to a normally informative trigger feature, an individual preserves crucial time, energy, and mental capacity. The disadvantage of such

responding lies in its vulnerability to silly and costly mistakes; by reacting to only a piece of the available information (even a usually predictive piece), an individual increases the chances of error, especially when responding in an automatic, mindless fashion. The chances of error increase even further when other individuals seek to profit by arranging (through manipulation of trigger features) to stimulate a desired behavior at inappropriate times. Much of the compliance process (wherein one person is spurred to comply with another person’s request) can be understood in terms of a human tendency for automatic, shortcut responding. Most of us have developed a set of trigger features for compliance—that is, specific pieces of information that normally tell us when compliance with a request is likely to be correct and beneficial. Each of these trigger features for compliance can be used like a lever (of influence) to move people to agree with requests. Perceptual contrast—the tendency to see two things that are different from one another as being more different than they actually are—is a lever of influence used by some compliance

practitioners. For example, real-estate agents may show prospective home buyers one or two unattractive options before showing them a more attractive home, which then seems more attractive than it would have if shown first. An advantage of employing this lev...

The rule says that we should try to repay what another person has provided us.

conscientious” scientists know better. One reason they know better is that these “smart, mature, sophisticated men and women at the top of their [scientific] professions” have found themselves to be as susceptible as anyone else to the process.

According to sociologists and anthropologists, one of the most widespread and basic norms of human culture is embodied in the rule of reciprocation. The rule requires that one person try to repay, in form, what another person has provided. By obligating the recipient of an act to repayment in the future, the rule allows one individual to give something to another with confidence that it is not being lost. This sense of future obligation within the rule makes possible the development of various kinds of continuing relationships, transactions, and exchanges that are beneficial to society. Consequently, all members of all societies are trained from childhood to abide by the rule or suffer serious social disapproval. The decision to comply with another’s request is frequently influenced by the reciprocity rule. One favorite and profitable tactic of certain compliance professionals is to give something before asking for a return favor. The exploitability of the tactic is due to three characteristics of the rule of reciprocation. First, the rule is extremely powerful, often overwhelming the influence of other factors that normally determine compliance with a request. The rule becomes particularly potent when the gift, favor, or service is personalized or customized to the recipient’s current preferences

or needs. Second, the rule applies even to uninvited first favors, thereby reducing our ability to decide whom we wish to owe and putting the choice in the hands of others. Finally, the rule can spur unequal exchanges; to be rid of the uncomfortable feeling of indebtedness, an individual often agrees to a request for a substantially larger favor than the one he or she received. Another way the rule of reciprocation can increase compliance involves a simple variation on the basic theme: instead of providing a first favor that stimulates a return favor, an individual can make an initial concession that stimulates a return concession. One compliance procedure, called the rejection-then-retreat technique, or door-in-the-face technique, relies heavily on the pressure to reciprocate concessions. By starting with an extreme request sure to be rejected, a requester can then profitably retreat to a smaller request (the one desired all along), which is likely to be accepted because it appears to be a concession. Research indicates that aside from increasing the likelihood a person will say yes to a request, the rejection-then-retreat technique also increases the likelihood the person will carry out

the request and agree to such requests in the future. This is the case because, after participating in a reciprocal exchange of concessions, people feel more responsible for and more satisfied with the outcome. Our best defense against the use of reciprocity pressures to gain our compliance is not systematic rejection of the initial offers of others. Rather, we should accept initial favors or concessions in good faith but be ready to redefine them as tricks should they later be proved ...

Thus, it’s a fool’s errand to try to overcome faith-based, emotionally held beliefs with logical argumentation, as each represents a separate way of knowing. The British writer Jonathan Swift saw it three hundred years ago and declared, “It is useless to attempt to reason a man out of a thing he was never reasoned into”—and

People prefer to say yes to individuals they like. Recognizing this rule, compliance professionals

commonly increase their effectiveness by emphasizing several factors that increase their overall likability. One such feature is physical attractiveness. Although it has long been suspected that physical beauty provides an advantage in social interaction, research indicates the advantage may be greater than supposed. Physical attractiveness engenders a halo effect that leads to the assignment of other traits such as talent, kindness, and intelligence. As a result, attractive people are more persuasive both in terms of getting what they request and changing others’ attitudes. A second factor that influences liking and compliance is similarity. We like people who are like us, and we are more willing to say yes to their requests, often in an unthinking manner. Another such factor is praise. Compliments generally enhance liking and, hence, compliance. Two particularly useful types of genuine compliments are those delivered behind the recipient’s back and those selected to give the recipient a reputation to live up to, by continuing to perform the desired behavior.

Increased familiarity through repeated contact with a person or thing is yet another factor that normally facilitates liking. This relationship holds true principally when the contact takes place under positive rather than negative circumstances. One positive circumstance that works especially well is mutual and successful cooperation. A fifth factor linked to liking is association. By connecting themselves or their products with positive things, advertisers, politicians, and merchandisers frequently seek to share in the positivity through the process of association. Other individuals as well (sports fans, for example) appear to recognize the positive effect of simple connections and try to associate themselves with favorable events and distance themselves from unfavorable events in the eyes of observers. A potentially effective strategy for reducing the unwanted influence of liking on compliance decisions r...

his or her offer, and make any compliance decision based solely on th...

There is a phenomenon called claquing, said to have begun in 1820 by a pair of Paris opera-house habitués named Sauton and Porcher. The men were more than operagoers, though. They were businessmen whose product was applause; and they knew how to structure social proof to incite it.

This account provides certain insights into the way we respond to social proof. First, we seem to assume that if a lot of people are doing the same thing, they must know something we don’t. Especially when we are uncertain, we are willing to place an enormous amount of trust in the collective knowledge of the crowd. Second, quite frequently the crowd is mistaken because its members are not acting on the basis of any superior information but are reacting, themselves, to the principle of social proof.

The principle of social proof states that one important means people use to decide what to believe or how to act in a situation is to examine what others are believing or doing there. Powerful such effects have been found among both children and adults and in such diverse activities as purchase decisions, charity donations, and phobia remission. The principle of social proof can be used to stimulate a person’s compliance with a request by communicating that many other individuals (the more, the better) are or have been complying with it. Therefore, simply pointing to the popularity of an item elevates its popularity. Social proof is most influential under three conditions. The first is uncertainty. When people are unsure, when the situation is ambiguous, they are more likely to attend to the actions of others and to accept those actions as correct. In ambiguous situations, for instance, the decisions of bystanders to offer emergency aid are much more influenced by the actions of other bystanders than when the situation is a clear-cut emergency. A second condition under which social proof is most influential involves “the many”: people are more inclined to follow the lead of others in proportion to the others’ number. When we see multiple others performing an action, we become willing to follow because the action appears to be more (1) correct/valid, (2) feasible, and (3) socially acceptable. The third optimizing condition for social-proof information is similarity. People ...

The effectiveness of this approach has been documented in (1) legal settings, where a trial attorney who admits a weakness before the rival attorney points it out is viewed as more credible and wins more often; (2) political campaigns, where a candidate who begins with something positive to say about a rival (such as, “I am sure my opponent has the best of intentions with that proposal, but . . .”) gains trustworthiness and voting preferences; and (3) advertising messages, where merchandisers who acknowledge a drawback before highlighting strengths often see large increases in sales. After Domino’s “NEW DOMINO’S” campaign of 2009 admitting to the past poor quality of its pizza, sales went sky high; as a consequence, so did Domino’s stock price.

In the Milgram studies, we see evidence of strong pressures for compliance with the requests of an authority. Acting contrary to their own preferences, many normal, psychologically healthy individuals were willing to deliver dangerous levels of pain to another person because they were directed to do so by an authority figure. The strength of the tendency to obey legitimate authorities comes from systematic socialization

practices designed to instill in members of society the perception that such obedience constitutes correct conduct. In addition, it is adaptive to obey the dictates of genuine authorities because such individuals usually possess high levels of knowledge, wisdom, and power. For these reasons, deference to authorities can occur in a mindless fashion as a kind of decision-making shortcut. When reacting to authority in an automatic fashion, people have a tendency to do so in response to mere symbols of authority rather than to its substance. Three kinds of symbols effective in this regard are titles, clothing, and trappings such as automobiles. In studies, individuals possessing prestigious forms of one or another of the symbols (and no other legitimizing credentials) were accorded more deference or obedience by those they encountered. Moreover, in each instance, those individuals who deferred or obeyed underestimated the effect of the authority pressures on their behaviors. Authority influence flows from being viewed as either in authority or an authority. But the first of these types, merely being in charge, has its problems. Ordering people to do things

often generates resistance and resentment. The second type of authority, being viewed as highly informed, avoids this problem, as people are usually willing to follow the recommendations of someone who knows more than they do on the matter at hand. The persuasive effect of being seen as an authority is maximized by also being seen as a credible such authority—one perceived as both expert (knowledgeable on the relevant topic) and trustworthy (honest in the presentation of one’s knowledge). To establish their trustworthiness, communicators may admit to a (usually minor) shortcoming of their case, which can be swept aside later by the presentation of outweighing strengths. It is possible to defend ourselves against the detrimental effects of authority influence by asking two questions: Is this authority truly an expert? and How truthful can we expect this expert to be? The first directs our attention away from symbols and toward evidence for authority status. The second advises us to consider not just the expert’s knowledge in the situation but also his or her trustworthiness. With regard to this se...

According to the scarcity principle, people assign more value to opportunities that are less available. The use of this principle for profit can be seen in such compliance techniques as the “limited number” and “deadline” tactics, wherein practitioners try to convince us that if we don’t act now, we will lose something of value. This engages the human tendency for loss aversion—that people are more motivated by the thought of

losing something than by the thought of gaining something of equal value. The scarcity principle holds for two reasons. First, because things difficult to attain are typically more valuable, the availability of an item or experience can serve as a shortcut cue to its quality; and, because of loss aversion, we will be motivated to avoid losing something of high quality. Second, as things become less accessible, we lose freedoms. According to psychological reactance theory, we respond to the loss of freedoms by wanting to have them (along with the goods and services connected to them) more than before. As a motivator, psychological reactance is present throughout the great majority of the life span. However, it is especially evident at a pair of ages: the terrible twos and the teenage years. Both of these times are characterized by an emerging sense of individuality, which brings to prominence issues of control, rights, and freedoms. Consequently, individuals at these ages are especially averse to restrictions. In addition to its effect on the valuation of commodities, the scarcity principle also applies to the

way information is evaluated. The act of limiting access to a message causes individuals to want to receive it and to become more favorable to it. In the case of censorship, the effect of greater favorability toward a restricted message occurs even before the message has been received. In addition, messages are more effective if perceived as containing exclusive (scarce) information. The scarcity principle is most likely to hold under two optimizing conditions. First, scarce items are heightened in value when they are newly scarce. That is, we value those things that have recently become restricted more than we do those that were restricted all along. Second, we are most attracted to scarce resources when we compete with others for them. It is difficult to steel ourselves cognitively against scarcity pressures because they have an emotion-arousing quality that makes thinki...

Every time you make a choice, you are turning the central part of you, the part that chooses, into something a little different from what it was before. —C. S. Lewis

Psychologists have long recognized a desire in most people to be and look consistent within their words, beliefs, attitudes, and deeds. This tendency for consistency is fed from three sources. First, good personal consistency is highly valued by society. Second, aside from its effect on public image, generally consistent conduct provides a beneficial approach to daily life. Third, a consistent orientation affords a valuable shortcut through the complexity of modern existence. By being consistent with earlier decisions, one reduces the need to process all the relevant information in future similar situations; instead, one merely needs to recall the earlier decision and to respond consistently with it. Within the realm of compliance, securing an initial commitment is the key. After making a commitment (that is, taking an action, stand, or position), people are more willing to agree to requests in keeping with the prior commitment. Thus, many compliance professionals try to induce people to take an initial position that is consistent with a behavior they will later request from these people. Not all commitments are equally effective in producing consistent future action. Commitments are most effective when they are active, public, effortful, and viewed as internally motivated (voluntary), because each of these elements changes self-image. The reason they do so is that each element gives us information about what we must truly believe. Commitment decisions, even erroneous ones...

Inside these identity-merged groups, unity trumps truth. Said differently, and in less politically loaded language, deception that strengthens a “we”-group is viewed by members as morally superior to truth-telling that weakens their group.

Political parties exhibit a festering form of the problem. As one reviewer of relevant research concluded: “This kind of lying [for political gain] seems to thrive in an atmosphere of anger, resentment and hyper-polarization. Party identification is so strong that criticism of the party feels like a threat to the self, which triggers a host of defensive psychological mechanisms.”

As distinguished author Isaac Asimov put it in describing our reactions to contests we view: “All things being equal, you root for your own sex, your own culture, your own locality . . . and what you want to prove is that you are better than the other person. Whomever you root for represents you; and when he [or she] wins, you win.” Viewed in this light, the intense passion of sports fans makes sense. The game is no light diversion to be enjoyed for its inherent form and artistry. The self is at stake. That is why hometown crowds are so adoring and, tellingly, so grateful to those responsible for home-team victories. That is also why the same crowds are often ferocious in their treatment of players, coaches, and officials implicated in athletic failures.

People say yes to someone they consider one of them. The experience of “we”-ness (unity) with others is about shared identities—tribe-like categories that individuals use to define themselves and their groups, such as race, ethnicity, nationality, and family, as well as political and religious affiliations.

Research into “we”-groups has produced three general conclusions. Members of these groups favor the outcomes and welfare of fellow members over those of nonmembers. “We”-group members also use the preferences and actions of fellow members to guide their own, which enhances group solidarity. Finally, such partisan tendencies have arisen, evolutionarily, as ways to

advantage our “we”-groups and, ultimately, ourselves. These three constants have surfaced in a wide range of domains, including business, polit...

is one fundamental factor leading to feelings of “we”-ness. This perception is generated by commonalities of kinship (amount of genetic overlap) as well as by commonalities of place (including one’s home, locality, and region). The experience of acting together in unison or coordination is a second fundamental factor leading to a sense of unity with others. Shared musical experience is one way people can act together and feel consequent unity. Other ways involve repeated reciprocal exchange, joint suffering, and co-creation. It may be possible to use the unifying effects of belonging together and acting together to increase the odds of getting together as a spec...

Other kinds of connections involving national identity, mutual enemies, joint emotional experience, and shared perspective can also lead to feelings of unity with out-group members; unfortunately, they are often short-lived. However, focusing concentrated, repeated attention on such conne...