Understanding how people persuade others is essential knowledge for anybody who does not want to be manipulated by others. From salespeople trying to sell you their products to politicians vying for your vote, many professionals use influence tactics to get what they want from you. How can you defend yourself from this onslaught of highly researched persuasion tactics?

Enter Robert Cialdini.

Cialdini is a psychology researcher who has studied the various ways in which people influence each other for over 35 years. In this book, he synthesized what he learned by identifying six key ways in which people influence others.

The key principle behind all persuasion tactics is the following: We face an deluge of information that is increasing more and more in complexity. In order to make decisions in a reasonable amount of time, we employ heuristics that work most of the time but are shortcuts that can be exploited. Influencers understand these heuristics and construct situations where your instincts lead you astray. The defense is simple: understand how to recognize these situations and adjust your decision making accordingly.

The summaries of the principles are described in the following form:

  • Principle
    • The heuristic in plain english.
    • Why that heuristic generally makes sense to use.
    • How it can be exploited by salespeople.
    • More interesting notes from the chapter.

Chapter Summaries

  • Chapter 1: The Weapons of Influence:

This chapter serves an introduction. The key point throughout the book is that making decisions in the real world is difficult due to a lack of information. Thus we need to use heuristics to make decisions. By knowing the heuristics that you or me use, those who wield the power of influence can create situations where our use of heuristics leads us to make poor decisions. Furthermore, these responses are mostly automatic and people do not realize that they are being manipulated when they are used (except possibly after the fact).

As a concrete example, he describes the contrast principle. The basic idea is that if you don’t know the value of something, you’ll rely on the relative prices of things to determine what to buy. For instance, stores often put expensive things in the front of the store so that when people find cheaper things in the back, they feel like they found a deal even though the expensive items in the front weren’t intended to be sold in the first place.

  • Chapter 2: Reciprocation
    • If you are nice to me, I should be nice to you.
    • Working together tends to produce better results. Also it serves as a way to introduce yourself to others. Also there is a high social penalty for not reciprocating gifts.
    • A salesperson can give you something, then you feel obligated to return by buying something even if it is much higher value than the offered item.
    • Offering somebody something can create uninvited debts so much so that people will refuse to accept things from strangers because they are worried about being indebtted to them. Another interesting example is to for a car salesman to give you a snack before selling you a car. In this situation, they gain the benefits of the reciprocity rule but they are offering something of much lower value.
  • Chapter 3: Commitment and Consistency
    • If I said that I’d do something, I should do it. AND if I have worked hard for something, then that something is worth having.
    • If other people percieve you to be consistent, they are more likely to work with you. AND Things that are valuable take a long time to attain.
    • A salesperson can get you to agree to a set of larger and larger commitments, ending with buying something.
    • One of the key points here is that in order to harness this technique, you can ask people to commit to larger and larger things over time. In order for the person to maintain consistency, they have to keep accepting the commitments. The chapter also discusses using public commitments in order to get people to stick to their goals and agreements. The last part of the chapter discussed hazing and initiation rights. The basic point there is that if somebody has put a lot of work towards attaining something, then they are much more committed to it (eg. sunk cost fallacy). Intense initiation rights exist in many different times and places such as tribal initiations, fraternity hell weeks and military bootcamps. The changes based on these tactics can be long lasting because people see part of their identity as tied to the hardship that they had to endure.
  • Chapter 4: Social Proof
    • If other people like something, it must be good.
    • It is generally reasonable to trust the opinion of other people (especially those who are trustworthy and or similar to me).
    • Salespeople can manipulate the testimonials by either hiring actors or only telling you the positive ones.
    • There are many situations where people rely on others for making decisions in an unconscious way. For instance, in the bystander effect, if someone is screaming for help where there is a large crowd, people often do nothing. According to the social proof theory, people look to others, see them doing nothing and figure that they also don’t need to do anything as well. Another interesting example is that people find things more funny if there is a laugh track or somebody hired to laugh in the audience (claquing). The chapter continues to describe how suicides and fatal accidents increase after the news talks about somebody who commits suicide. Finally, it is crucial to note that that people are more likely to look to others for how to behave in situations of high uncertainty. This helps explain how cult leaders lead people to mass suicide.
  • Chapter 5: Liking
    • I treat people who I like nicely.
    • If I treat others nicely, then they will treat me nicely.
    • Salespeople can exploit our biases in liking such as being attractive, being similar to us, etc.
    • One of the main focuses of this chapter is that we have a lot of different biases related to liking people. The main categories that he focuses on are similarity, familarity, attractiveness and people who give you complements. The last part of the chapter was about race relations and how to structure situations so that people like each other. When people initially integrated schools, they thought that students would get along if they were together for long enough. It turned out that simple contact didn’t work and high pressure situations in school made things worse. There is some research that shows that creating a situation that forces cooperation can build relationships.
  • Chapter 6: Authority
    • I should do what authority says.
    • Somebody who has power over me can make life harder for me if I don’t listen to them.
    • Salespeople can act in ways that seem like they have authority even if they really don’t know what they are talking about.
    • The focus of this chapter is the Milgram study. There are other places that describe this study in more detail. The basic idea is that people would shock another person when a doctor told them even when hearing screams from the other person. It turns out that the screams were fake but the power of the authority was able to make people cause others pain. One of the reasons that people did this study was to better understand Nazi Germany.
  • Chapter 7: Scarcity
    • If something is scarce, it must be good.
    • If something is good, then it will be scarce.
    • Salespeople can artifically make something seem scarce.
    • The first major sales tactic related to scarcity is creating artificial deadlines or saying that something is going to sell out. Another related principle is the idea that people don’t want to give up things that they have even if they don’t use them. Finally, sometimes people use reverse psychology by restricting people’s access to something. Then since that thing seems scarce, people will want it more.

Conclusion

Now, more that ever, it is crucial to understand the methods of influence that people in positions of power will use to gain your support. Anybody who does politics is well aware of all of these tactics of persuasion and use them constantly. If you read this book, you can learn more about how to see through the manipulation and make the best decisions that you can. I would definitely enjoy to see an updated version of this book that used contemporary examples (eg. politics).

Another modern area of persuasion that would be exciting to learn about is they dynamics created by large groups of people and big data. For instance, more than ever before, ideas go viral. There is much more to understand as to how this happens. Another interesting method of persuasion that is common on news aggregators is as follows. Start with a large collection of content, then let people choose what they click on, and amplify the content that gets clicks. Using this method, we have no idea why people choose what they choose and it creates potential ethical issues. For instance, these methods can lead to a reinforcing cycle of polarization and lacks the quality of curated content.

In summary, this book is very useful for understanding the fundamentals of persuasion that we see everywhere in life. I highly recommend reading this book as it helps us better understand the ever increasing deluge of information in the modern world.