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Influence Summary

6 min read ⌚ 

Do you want to find out which are the most effective techniques that create compliance? Or what are the factors that makes a person say yes to another person? What stands behind the persuasion mechanism? Which are its triggers?

Jump from curiosity to knowledge and start reading Influence: The Psychology of Persuasion by Robert Cialdini. We’ve pulled the main ideas in the book summary below.

With over 30 years of research into the science of influence, Dr. Robert Cialdini has earned an international reputation as an expert in the fields of persuasion, compliance, and negotiation. His 1984 book, Influence, nowadays a classic of the genre, has sold over two million copies and has been translated into twenty-six languages.


There are six universal principles that determine if people will change behavior: reciprocity, commitment, social proof, liking, authority, and scarcity.

Robert Cialdini began to do research into the psychology of compliance in his role as an experimental social psychologist. With Influence his purpose was to find out which psychological principles influence the tendency to comply with a request. In order to do that, he observed, from the inside, the techniques and strategies most commonly and effectively used by compliance practitioners by spending three “undercover” years training at used car dealerships, fund-raising organizations, and telemarketing firms to observe real-life situations of persuasion.

The book is divided into 7 chapters plus an epilogue and explores the main principles and weapons of influence. Although there are thousands of different tactics that compliance practitioners employ to produce yes, the majority fall within six basic categories. Each of these categories is governed by a fundamental psychological principle that directs human behavior and, in so doing, gives the tactics their power.

The book is organized around these six principles, one for each chapter. The principles are consistency, reciprocation, social proof, authority, liking, and scarcity. One by one is discussed in terms of its function in society and in terms of how its powerful force can be summoned by compliance professionals.

I personally loved the way each principle is examined by its ability to produce a distinct kind of automatic, mindless compliance from people. A willingness to say yes without thinking first.

Another thing that struck me while reading Influence was the way that Robert Cialdini broadened his area of research by taking interviews with the practitioners.. By default, the people working in sales or marketing know what works for them and what doesn’t, and this is precisely why the insights gained from this book are so powerful.

Automatic behavior patterns make us terribly vulnerable to anyone who knows how they work. There are several groups of people who know very well where the weapons of automatic influence lie. So all they have to do is to employ them regularly to get what they want.

In the first chapter, we see how weapons of influence posses a tremendous ability to direct human action. One of the secret of their effectiveness lies in the structure of their requests. In the way that compliance professionals arm themselves with one or another of the weapons of influence that exist within the social environment.

Influence Summary

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.

An additional skill that’s fundamental in being a compliance professional is the ability to manipulate without the appearance of manipulation. I’m sure you can think of a time when you found yourself complying with someone’s request while thinking that you said “yes” due to the action of natural forces rather than by the skills of those that profited over that compliance.

The contrast principle is another factor that affects the way we see the difference between two things that are presented one after another. This happens because the same thing can be made to seem very different, depending on the nature of the event that precedes it.

Chapter 2 of the book presents us one of the most potent of the weapons of influence around us—the rule for reciprocation. The rule states that we should try to repay, in kind, what another person has provided us.

'Reciprocation can be used effectively as a device for gaining another’s compliance.' /robert-cialdini-influence-get-your-mind-in-other-minds/ Click To Tweet

The reciprocation rule is so widespread that after intensive study, sociologists such as Alvin Gouldner reported that there is no human society that does not subscribe to the rule.

One of the reasons reciprocation can be used so effectively as a device for gaining another’s compliance is its power. The rule possesses awesome strength, often producing a “yes” response to a request that without the feeling of indebtedness would have been declined.

Although the number of possible examples where this rule is applied is large, the one that may be most familiar to you is the “free sample”. This came as an answer to the desire of the manufacturer to expose the public to the qualities of the product. But the power of the free sample is actually that it represents a gift and it engages the reciprocity rule.

In chapter 3, Robert Cialdini examines another rule that lies deep within us, directing our actions with quiet power, the need for consistency and commitment. Once we have made a choice, we will encounter personal and interpersonal pressures to behave consistently with that commitment. Those pressures cause us to respond in ways that support our earlier decision.

'The desire for consistency is a central motivator of our behavior' @RobertCialdini /robert-cialdini-influence-get-your-mind-in-other-minds/ Click To Tweet

It is not hard to understand, then, why automatic consistency is a difficult reaction to defeat. It offers us a way to escape the rigors of continuing thought. And, as Sir Joshua Reynolds noted, “There is no expedient to which a man will not resort to avoid the real labor of thinking.”

For the salesperson, the strategy is to obtain a large purchase by starting with a small one. Almost any small sale will do, because profit is not the purpose of that small transaction. It is commitment. Further purchases are expected to flow naturally because of the commitment made. This tactic of starting with a little request in order to gain eventual compliance with related larger requests is called the foot-in-the-door technique.

Also keep in mind that the more effort that goes into a commitment, the greater is its ability to influence the attitudes of the person who made it.

In chapter 4, Robert Cialdini discovers yet another potent weapon of influence: the principle of social proof. This principle states that one way we use to determine what is correct is to find out what other people think is correct. Whether the question is what to do with an empty popcorn box in a movie theater or how to eat the chicken at a dinner party, the actions of those around us are important in defining the answer.

In Chapter 5, Robert Cialdini explores liking and its power as a weapon of influence. One example of a situation where this works is the endless chain method. Once a customer admits to liking a product, he or she can be pressed for the names of friends who would also appreciate finding out about it.

The individuals on that list can then be approached for sales and a list of their friends, who can serve as sources for still other potential customers, and so on in an endless chain.

Influence PDF

The widespread use by compliance practitioners of the liking bond between friends tells us much about the power of the liking rule to produce assent.

In fact, we find that such professionals seek to benefit from the rule even when already formed friendships are not present for them to employ. Under these circumstances, the professionals’ compliance strategy is quite direct: They first get us to like them.

In Chapter 6 we see how authority influences the way we make decisions. Although a multi-layered and widely accepted system of authority confers an immense advantage upon a society, in some cases our obedience to authority takes place in a click, without any conscious deliberation.

Chapter 7 explores scarcity – the rule of the few. The scarcity principle states that opportunities seem more valuable to us when their availability is limited.

In making our compliance decisions we employ the factors of reciprocation. Of consistency. Of social proof & liking. Authority and scarcity. And we do it so often and so automatically because each, by itself, provides a highly reliable cue as to when we will be better off saying “yes” than “no”.

Those may be enough reasons to be aware of these weapons of influence, and to read Robert Cialdini ’s amazing book.

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