Influence — 7 minute summary

Here are my key highlights taken from the book Influence by Robert B. Cialdini. You should read this post (and perhaps the book) if you are interested in how people get you to do things that you don’t want to do and how to protect yourself against their techniques.

In this summary, I answer four questions:

  1. What is this book about?
  2. What are the main ideas and arguments?
  3. What is my opinion on the book?
  4. What was the significance of reading this book?

What is this book about?

This is a practical book about the techniques that people/businesses use to influence you, and how you can take proactive measures against them or how to respond to them. The author wrote this book because he was a victim of these techniques and wants to educate the public on how to defend against them when used by those with selfish intentions.

The thesis of the book is that influence professionals (e.g., salespeople) use techniques that are based on a variety of compliance principles to make us happily comply with their requests. These techniques aren’t inherently bad; in fact, many of them are helpful for evolution. But they can be used for negative intentions when held by the wrong hands, so we need to be aware of them and how to defend against them.

What are the main ideas and arguments?

The book centers around seven compliance principles:

Note 1: The author doesn’t formally list the contrast principle in his list, but he does describe it and provide examples, so I included it in this list.

Note 2: There’s another principle that is self-explanatory, which is that we tend to do whatever is in our self-interest.

Note 3: On liking, the author identifies five factors that make people like someone: physical attractiveness, similarity, giving compliments, cooperation, and conditioning. The first three are self-explanatory. Cooperation refers to working together and being on the same team, such as when the salesperson “fights” against his boss for you. Conditioning refers to linking a product to something you like, such as having a popular athlete sponsor a soft drink.

Can you identify the compliance principle(s) used?

Answers are at the end of the post.

Situation 1: A company lets you try their product for free for 30 days. You can cancel after that with no questions asked. But of course, some people will feel bad about cancelling and will instead buy the product.

Situation 2: An online class is only available for registration for the next 2 weeks, and because you’re on the exclusive mailing list, you can get 15% off if you register in the next 3 days!

Situation 3: The real estate agent first shows you an expensive, not-so-nice house. Then she shows you the house she’s actually trying to sell. Now, the second one seems way nicer and well-priced than it would’ve if the agent showed you that one first.

Situation 4: A physically attractive car salesperson talks about how you two both like golf, gives you compliments, does you a favour by fighting with the boss for a better price for you, and then finally asking you accept his best price.

Situation 5: A toothpaste company runs a commercial with dentists recommending their products.

Situation 6: Your university’s alumni relations department asks you to donate a small amount to your school. Then in future years, they hope to count on you to consistently donate and maybe even donate larger amounts.

Situation 7: Companies run testimonial contests so that customers who are just like you tell you that the product is great. Moreover, those writing the testimonials also feel better about the product.

Situation 8: A girl scout asks you to donate $20. You say no. Now she asks if you can buy a $3 chocolate bar instead.

Situation 9: Comedy shows use canned laughter to get the audience to laugh more and think the show is funnier. Despite criticisms of the technique, it really does improve ratings.

Situation 10: A toy manufacturer heavily promotes a certain toy before Christmas so that kids asks their parents for it. Then, the company undersupplies the toy in stores so parents have to buy substitute toys of equal value. After Christmas, they run the ad for that toy again, so the kids say “you promised you’d get it for me” and then the parents have to go back to the store to buy the toy.

Situation 11: Comedy shows put on canned laughter to signal to the viewer that they should be laughing too. Despite criticisms of the tactic, it really does improve ratings of the show.

Situation 12: A person trying to sell their car invites you to come check it out. Five minutes after you arrive, you see someone else arrive. The seller tells that person to wait until her turn and that the person before her needs to get his chance to look at the car and make his decision first. The seller then turns to you and tells you to take your time and then let him know if you want to buy it or not.

Situation 13: A car salesperson tells about a special event that makes you qualify for a great discount. You are very excited about the discount so you work together to pick a car that meets all your wants. The salesperson goes to draft the final contract for you to sign. After he comes back, he tells you that unfortunately, he found out you actually don’t qualify for the special discount, and asks if you still want to buy the car. During that time, your mind came up with many reasons for why the car is great, and you feel the urge to buy the car even without the discount.

Situation 14: A waiter tells you that she just checked with the chef and the option you ordered is not very fresh tonight. She suggests two other dishes that are fresh for the night, and they are both slightly cheaper. You feel like she is on your side. Later, you happily take her suggestions for drinks and desserts.

How to defend yourself against the compliance principles.

Defense against contrast: Ask yourself, “Is it possible that the first item was a setup for the second item?” If yes, then ask yourself, “If I was presented this item first, before the other item, how would I make my decision?”

Defense against reciprocity: We shouldn’t reject all gifts because that would result in hurting the person who is genuinely giving us a gift without alterior motives. Instead, we should accept gifts. If later, we are asked to repay in a fair way, then that’s fine and good for humanity. But if the ask is bigger, can we can view it as manipulation and then the reciprocation principle will no longer affect us. The battle is all in the head with reciprocity.

Defense against consistency: One way is to just call out the consistency principle is being used on you. The seller should realize he’s caught and back down. Another way is to ask yourself, “Knowing all that I know now, if I go back in time, would I make the same decision?”

Defense against social proof: Social proof is usually good for evolution because it allows us to learn from others’ experiences. When being sold something though, we should question if the social evidence is real or not. If it’s fake (like canned laughter), then we should ignore it.

Defense against liking: It’s very hard to prevent yourself from falling for their tactics, so instead, just focus on realizing when you’ve come to like someone much more quickly than expected. Then, you can separate the item from the seller. After all, you wouldn’t buy a bad item just because you like the seller if you were conscious of your choice.

Defense against fake authority: Ask yourself , “Is this authority truly a relevant expert?” If yes, then ask yourself, “How truthful can I expect this expert to be here?”

Defense against scarcity: Notice your increased heart rate and sweating, which warns you that scarcity may have been used on you. Then ask yourself why you really want the item. If you want the item just to own it, then don’t buy it. If you want the item for its utility, then remind yourself that it may not be better than a similar, non-scarce item.

What is my opinion on the book?

I think the book was very eye-opening for me and worth the time. It wasn’t a hard read because I could relate to most of the examples having experienced them myself. Now, when I get emails about a “limited time online class registration” or visit any sales page, I can identify the compliance tactics and not feel pressured to buy. It’s a great feeling.

I applaud the author for educating the public about these compliance principles. They can be used for good in the right hands, and they can be used by normal people to defend against those using the tactics for selfish intentions.

What was the significance of reading this book?

By reading this book, I was able to go from an ignorant victim of sales tactics to someone who understands them and is less fazed by them. I think it’s important for me to support the author’s work by trying to spread it to others.

— — —


1. Reciprocity

2. Scarcity

3. Contrast

4. Liking and a bit of reciprocity

5. Authority

6. Consistency; this tactic is called the foot-in-the-door tactic

7. Social Proof and consistency

8. Contrast and reciprocity; this tactic is called the larger-then-smaller-request technique

9. Social proof

10. Consistency

11. social proof

12. Scarcity and a bit of reciprocity

13. Consistency; this tactic is called the give-it-and-then-take-it-away-later tactic or lowballing

14. Authority

Passionate about self-cultivation, happiness, and sharing wisdom.