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Influence Summary PDF ePub Audio book by Robert Cialdini


Influence is a psychology book examining the key ways people can be influenced by “Compliance Professionals”. The book’s findings are backed up by numerous empirical studies conducted in the fields of psychology, marketing, economics, anthropology, and social science. Influence concludes that you can also adopt the approaches adopted by compliance professionals. Specifically, you can utilize the lessons provided in Influence to persuade others.

About Robert Cialdini

Robert Cialdini is the Regents’ Professor Emeritus of Psychology and Marketing at Arizona State University. He was a visiting professor of marketing, business, and psychology at Stanford University and the University of California at Santa Cruz. The Robert B. Cialdini Prize from the Society for Personality and Social Psychology is named after him in honor of psychological research that demonstrates societal relevance using field methods. He was elected a member of the National Academy of Sciences in April 2019.


“A well-known principle of human behavior says that when we ask someone to do us a favor we will be more successful if we provide a reason. People simply like to have reasons for what they do.”

– Robert Cialdini

A well-known principle of human behavior is that you will be more successful in seeking favors if you provide a reason. Harvard social psychologist, Ellen Langer, demonstrated this phenomenon by asking a minor favor of people waiting in line to use a library copying machine. She altered her request across contexts. Firstly, she said, “Excuse me, I have five pages. May I use the Xerox machine because I’m in a rush?” In this instance, she was highly successful. 94% of people who were asked in this way allowed her to skip ahead of them. Comparatively, only 60% did so when she said, “Excuse me. I have five pages. May I use the Xerox machine?”

The key difference between these statements was not the use of the word “rush”, though. Langer consolidated this finding when 93% of people let her skip when she said, “Excuse me, I have five pages. May I use the Xerox machine because I have to make some copies?” The key feature across the two successful contexts was using the word “because.”

Compliance Experts Who Utilize ‘Because’

There is a group of people who know very well where the weapons of automatic influence lie. Subsequently, they employ them regularly and expertly to get what they want. They go from social encounters to social encounters requesting others to comply with their wishes. Their frequency of success is remarkable. The secret of their effectiveness lies in the way they structure their requests and how they arm themselves with one or another of the weapons of influence that exist within the social environment. Their success may require no more than one correctly chosen word that engages a strong psychological principle and sets an automatic behavior in motion. 

The Contrast Principle

The contrast principle is well established in the field of Psychophysics and applies to multiple concepts besides weight. If we are talking to a beautiful woman at a cocktail party and are then joined by an unattractive one, the second woman will strike us as even less attractive than she actually is. When utilizing this principle to your benefit, you can benefit from the advantage of it being virtually undetectable. Those who employ it can cash in on its influence without any appearance of having structured the situation in their favor.


Retail clothiers are an excellent example of how the contrast principle can be used to influence others. Suppose a man enters a men’s clothing store and says he wants to buy a three-piece suit and a sweater. If you were the salesperson, which would you show him first to make him likely to spend the most money? Clothing stores instruct their sales personnel to sell the costly item first. Common sense might suggest the reverse: If a man has recently spent a lot of money to purchase a suit, he may be reluctant to spend much more on the purchase of a sweater. However, this assumption neglects the impact of the contrast principles. If you sell the suit first, when the man browses the sweaters, their prices will not appear as high in comparison. A man might balk at the idea of spending $95 for a sweater, but if he has just bought a $495 suit, a $95 sweater does not seem excessive.

The Six Principles of Persuasion

The 6 Principles of Persuasion

The 1st Weapon of Persuasion: Reciprocity

People feel obliged to give back to others in the form of a behavior, gift, or service they have received first. If a friend invites you to their party, there’s an obligation for you to invite them to a future party you are hosting. If a colleague does you a favor, then you owe that colleague a favor. Hence, in the context of a social obligation, people are more likely to say yes to those who they owe.

The Sample Tactic

The sample tactic is an effective tool that takes advantage of the weapon that is reciprocity. Amway Corporation is a rapid-growth company that manufactures and distributes household and personal-care products in a vast national network of door-to-door neighborhood sales. The company has grown from a basement-run operation a few years ago to a business with yearly sales in the billions of dollars. They make use of the free sample in a device called the BUG.

The BUG consists of a collection of Amway products—bottles of furniture polish, detergent, or shampoo, spray containers of deodorizers, insect killers, or window cleaners. These items are carried to the customer’s home in a specially designed tray or simply a polyethylene bag. The confidential Amway Career Manual then instructs the salesperson to leave the BUG with the customer “for 24, 48, or 72 hours, at no cost or obligation to her. Just tell her you would like her to try the products… That’s an offer no one can refuse.”

At the end of the trial period, the Amway representative returns and picks up orders for those of the products the customer wishes to purchase. Since few customers use up the entire contents of even one of the product containers in such a short time, the salesperson may then take the remaining product portions in the BUG to the next potential customer down the line or across the street and start the process again. Many Amway representatives have several BUGs circulating in their districts at one time. The customer who has accepted and used the BUG products has been trapped into facing the influence of the reciprocity rule. Many customers feel obligated to order those of the salesperson’s products that they have partially consumed.

The 2nd Weapon of Persuasion: Scarcity

Simply put, people want more of what they struggle to acquire. People seem more motivated by the thought of losing something than by the thought of gaining something of equal value.

Consider when British Airways announced in 2003 that they would no longer be operating their twice-daily London—New York Concorde flight because it had become uneconomical to operate. With only one flight available, sales for this flight took off. Notice that nothing had changed about the Concorde itself. The plane didn’t fly any faster, the service didn’t suddenly get better, and the airfare didn’t drop. Instead, this flight route had simply become a scarce resource. Consequently, people wanted it more.

Similarly, pamphlets urging young women to check for breast cancer through self-examinations are significantly more successful if they state their case in terms of what stands to be lost rather than gained. For example, talking about the potential of losing a breast if you do not self-examine is one of the most convincing approaches.

The realization that we value limited information allows us to apply the scarcity principle to realms beyond material commodities. The principle also works for messages, communications, and knowledge. Taking this perspective, we can see that information does not have to be censored for us to value it more; it need only be scarce. According to the scarcity principle, then, we will find a piece of information more persuasive if we think we can’t get it elsewhere.

The 3rd Weapon of Persuasion: Authority

The authority weapon is based on the idea that people follow the lead of credible, knowledgeable experts.

For example, physiotherapists can persuade more of their patients to comply with recommended exercise programs if they display their medical diplomas on the walls of their consulting rooms. Similarly, people are more likely to give change for a parking meter to a complete stranger if that requester wears a uniform rather than casual clothes.

On the worrying side, con artists drape themselves with the titles, clothes, and trappings of authority. In doing so, they are equipped to persuade you. Each of these symbols of authority has its own story and is worth a separate examination.


The authors describe titles as a paradox. Although they are difficult to legitimately acquire, they are the easiest symbol of authority to fake. It is possible for somebody who has put in no effort to adopt a label and receive automatic deference. TV-commercial actors and con artists benefit from this facade all the time.


The second kind of authority symbol that can trigger automatic compliance is clothing. Though more tangible than a title, the cloak of authority is every bit as fakable. In chameleon style, con artists can adopt the hospital white, priestly black, army green, or police blue that the situation requires. 


Aside from its function in uniforms, clothing can symbolize a more generalized type of authority when it serves an ornamental purpose. Finely styled and expensive clothes carry an aura of status and position. The same effect can also be harnessed through expensive jewelry and cars. In the United States, “the American love affair with the automobile” gives it particular significance.

The 4th Weapon of Persuasion: Consistency

“Often we don’t realize that our attitude toward something has been influenced by the number of times we have been exposed to it in the past.”

– Robert Cialdini

We like to be consistent with the things we have previously said or done. Like the other weapons of influence, this weapon lies deep within us. Our urge for consistency directs our actions with quiet power. It is, quite simply, our nearly obsessive desire to be (and to appear) consistent with what we have already done.

Once we have made a choice or taken a stand, we will encounter personal and interpersonal pressures to behave consistently with that commitment. Those pressures will cause us to respond in ways that justify our earlier decision. Consistency is activated by searching for, and asking for, minor initial commitments that can be made. In a famous set of studies, researchers found that very few people are willing to erect an unsightly wooden board on their front lawn to support a Drive Safely campaign. However, in a similar neighborhood close by, four times as many homeowners indicated they would be willing to erect this unsightly billboard. The only difference is that ten days previously, they had agreed to place a small postcard in the front window of their homes. This postcard signaled their support for a Drive Safely campaign. That small card was the initial commitment that led to a 400% increase in a much bigger but still consistent change.

How Big Toy Companies Increase their January-February Sales

Toy companies start their pursuit of new year sales before Christmas. At this stage, they produce and release attractive TV ads for certain special toys. The kids, naturally, want what they see. Children then obtain a promise from their parents that they will get this toy for Christmas. However, little do the parents know that the companies deliberately undersupply the stores with the advertised toys. Most parents find those objects sold out and are forced to substitute other toys of equal value. Of course, the toy manufacturers make a point of supplying the stores with plenty of these substitutes. Then, after Christmas, the companies start rerunning the ads for the undersupplied toy. These adverts encourage the kids to want those toys more than ever. Children will then remind their parents that they promised. To remain consistent, parents will often go and buy this toy too.

Cold Callers Use Your Well-Being Against You

Callers asking you to contribute to a cause begin proceedings by inquiring about your current health and well-being. The caller’s intent with this introduction is not simply a way of seeming friendly. Instead, they are waiting for you to explain that you are fine. Any relatively positive response will lead to the caller’s next line of attack. Once you have publicly stated that all is well, it becomes much easier for the caller to corner you into aiding those for whom all is not well. The theory behind this tactic is that people who have just asserted they are doing/feeling fine will consequently find it awkward responding without considering their favored circumstances.

The 5th Weapon of Persuasion: Liking

People prefer to say yes to those that they like. Persuasion science tells us that there are three important factors that influence somebody’s likeability. We like people who are similar to us, we like people who pay us compliments, and we like people who cooperate with us towards mutual goals.

Physical Attractiveness

It is generally acknowledged that good-looking people have an advantage in social interactions. However, recent findings indicate we may have underestimated the size and reach of that advantage. Research has shown we automatically assign favorable traits to good-looking individuals, like talent, kindness, honesty, and intelligence. Furthermore, we make these judgments without being aware that physical attractiveness plays a role in the process.

Experiments have demonstrated that attractive people are more likely to get help when in need and are more persuasive in changing an audience’s opinions. This finding occurs irrespective of the sex of participants.


Being attractive means you have to be better looking than your average person. However, there are also ways you can utilize the weapon of liking as an average person. We like people who are similar to us. This fact seems to hold true whether the similarity is in opinions, personality traits, background, or lifestyle. Consequently, those who wish to be liked to increase compliance should appear like the chosen person in a wide variety of ways.

Dressing in a similar way to your target individual is a good example. Another way requesters can manipulate similarity to increase liking and compliance is to claim that they have similar backgrounds and interests similar.


We are phenomenal suckers for flattery. Although there are limits to our gullibility—especially when we can be sure that the flatterer is trying to manipulate us—we tend, as a rule, to believe praise and to like those who provide it, often when it is clearly false.

The 5th Weapon of Persuasion: Power of Associations

“There is a natural human tendency to dislike a person who brings us unpleasant information, even when that person did not cause the bad news. The simple association with it is enough to stimulate our dislike.”

– Robert Cialdini

Compliance professionals use associations to impact society’s buying behavior. This is why models are almost always chosen for product adverts. The advertiser hopes the model is lending their positive traits—beauty and desirability—to the product. The advertiser is betting that we will respond to the product in the same way we respond to the attractive models associated with it.

The linking of celebrities to products is another way advertisers cash in on the association principle. Professional athletes are paid to connect themselves to items that can be directly relevant to their roles (sports shoes) or wholly irrelevant (soft drinks). The important thing for the advertiser is to establish a connection. The connection doesn’t have to be a logical one, just a positive one.

The 6th Weapon of Persuasion: Consensus

When people are uncertain, they will look to others’ actions and behaviors to determine their own. Bartenders often “salt” their tip jars with a few dollar bills at the beginning of the evening to give the impression that tipping is common behavior. Church ushers often adopt a similar approach, while evangelicals often seed their audience with “ringers,” who give witness and donations.

Advertisers love to inform us when a product is the “fastest-growing” or “best-selling” because they don’t have to convince us directly that the product is good. Instead, they need only say that many others think so. This is often proof enough for consumers. The producers of charity telethons devote inordinate amounts of time to the continued listing of viewers who have already pledged contributions. The message being communicated is that giving is the right thing to do. 

Since 95 percent of people are imitators and only 5 percent initiators, people are persuaded more by others’ actions than by any proof we can offer. Therefore, when the situation is uncertain, we can assume people will accept the majority’s actions as correct. In the process of examining the reactions of other people to resolve our uncertainty, however, we are likely to overlook a subtle but important fact. Those people are probably examining the social evidence, too. Especially in an ambiguous situation, the tendency for everyone to be looking to see what everyone else is doing can lead to a fascinating phenomenon called “pluralistic ignorance.” Pluralistic Ignorance is a state in which each person decides that nothing is wrong since nobody is concerned. Meanwhile, the danger may be mounting. The reality is that a single individual, uninfluenced by the seeming calm of others, would react.

Comment below and let others know what you have learned or if you have any other thoughts.

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