52 in 52 Book Summaries

Book Summary: Influence by Robert Cialdini | Forces of Habit

Influence: The Psychology of Persuasion by Robert Cialdini


The Essence

Written in 1984, Influence is a classic in the fields of marketing and sales that validates and categorizes the six key principles of human influence. Our lives are ruled by the automatic behavior patterns that govern human nature. With more information than ever available, our brains compartmentalize models of action that make up a majority of the conscious decisions we make. These mental shortcuts have been harnessed as ‘Weapons of Influence’ by compliance practitioners to exploit what science has discovered about persuasion. Cialdini isolates each of the ways we tend to be manipulated and educates and then educates us how we can harness and shield ourselves from unwarranted sway. The best defense is a good offense and Cialdini provides us with the weapons to start a war.

Influence Summary Journal Entry:

This is my book summary of Influence by Robert Cialdini. My notes are a reflection of the journal write up above. Written informally, the notes contain a mesh of quotes and my own thoughts on the book. The Journal write up also includes important messages and crucial passages from the book.

  • We should not resist automatic behavior, it is fairly useful most of the time. But we ought to become mindful of the possibility that automatic behaviors have the ability to send us into set behaviors that manipulate our decision making.
  • Organisms are driven by Automatic behavior patterns. This is just a technical way to say we are animals of habit. And in the hands of manipulators, habits can be isolated and dissected to send us on down a set course of action; we are at the mercy of our habits.
  • By educating ourselves about the various form that influence can take, we can defend the ‘tricks of the trade’ that stimulate people to agree.

The Six Weapons of Influence


  • “If justice is to be done, exploitation attempts should be exploited.”
  • The rules of reciprocation require that one try to repay what another has provided them; these rules run deep in our ancestral past. So we tend to feel obligated to repay those who provide us with something. This is a device for manipulating the compliance of others.
  • Beware of the free sample! Free is never really free because still impacts of likelihood to reciprocate in the future.
    • Krishna benefactor-before-beggar strategy.
      By giving a flower before requesting a donation, the monks take advantage of the deeply rooted principle of reciprocation.
  • The reality of internal discomfort and the possibility of external shame produce a heavy psychological cost
  • Perceptual Contrast Principle: when you present stimuli one after another it can skew the proceeding choice. E.g. Price anchoring. If you give a consumer a high estimate price as for a product and then agree to ‘cut them a deal’ and do a lower price (the real price you are seeking), you increase the likelihood that your deal is positively perceived.

Commitment and Consistency

  • Staying consistent with how we internally view ourselves is a central motivator for future behavior. Making a choice or taking a position creates an interpersonal and intrapersonal pressure to behave in alignment with the previously announced commitment. The pressures of hypocrisy cause us to become swayed by our earlier decisions.
  • Foot in the door technique: Start with small requests and over time you’ll increase the likelihood of compliance for larger ones.
  • Get it in writing: make people write something down to limit the dissonance between future behavior and what they have written
  • Public commitments are commitments that last.
  • The more you put in, the more it matters. As we put more effort into our commitments they become larger influencers on our attitudes.

Social Proof

  • “Salt” the tip jar. By placing your own money in the tip jar initially it gives the impression that others are tipping and people will be more likely to tip due to social proof.
  • “Truths are us”: one of the ways that we gauge what to believe is through an internal crowdsourcing. We look towards others for information as to what the majority of people believe is true, and then we have the tendency to accept this as truth.
  • Embarrassment is a villain to be crushed.
  • As the number of people who believe an idea is correct increases, the more the idea will become ‘correct’. Studies have been done that show that when a group of actors and one participant answer questions with one another, the subject will go along with the clearly wrong answer because a majority of the group members (actors) believe it to be true.
  • Bystander effect: the legitimacy of an emergency can be based on the reaction of the surrounding audience. A woman was once stabbed in broad daylight while several people watched the crime. It is assumed that no one acted because no one else was acting. A distribution of concern across too many parties only breed inhibition.
  • To prevent this try to isolate individual in a crowd when seeking assistance. Make it direct, assign the task. If you have a medical emergency in a crowd, it would not be in your best interests to assume help will come because of the number of people present. Instead, single someone out saying “Hey man with blue shirt and staring right at me, please call 911!”
  • Social Proof influences us the most when we are observing people that we consider ‘just like us’.
  • Influential leaders take advantage of social proof be arranging group conditions to maximize sway in their favor.
  • We must become vigilant of information that is clearly attempting to sway our decision making using social agreement as a justification. For example, paying taxes because ‘70% of people in your neighborhood pay taxes’ is a ploy on your inclination to move with the crowd.


  • People prefer to say yes to the requests of people they know and like.
  • “We are phenomenal suckers for flattery.”
  • The Halo effect: a single positive characteristic becomes the primary justification for how a person is then perceived by others.
  • How we choose who we like is decided by several factors, can be boiled down to three things.
    • Similarities to ourselves.
    • Attractiveness.
    • Status.
  • A way to manipulate how you are perceived is to emphasize the number of similarities between one another. ‘Wow, I like breathing too! We have so much in common’.
  • How many times we have been exposed to something in the past has an impact on our attitudes towards it in the future. For instance, politician tends to send as many as five letters introducing themselves to the consistent. So when Election Day comes around, it's like we already know him; Familiarity breeds compliance.
  • The Principle of association: Our feelings on a given matter are guided by the things that we associate with that subject. For example, a news story goes viral about how you saved a kitten from a tree. Now those who have seen this story can associate you with good things (like saving kittens). While they know absolutely nothing about you, they use the information they have to associate with you to create broader assumptions about your personality and character.
  • People will try to sway us by making us team players. By establishing a connection that we are working towards a common goal for our mutual benefit, influencers play at our inclination towards agreeing with people who are ‘on our side’.
    • Good cop v. Bad Cop dichotomy: By presenting to contrasting figures to the criminal, the good cop seems comparatively nicer and the criminal may, therefore, feel more agreeable and give the officer exactly what he wants.
  • In cases that lower our status, we purposefully do not identify as a member of groups that are found to be the losing party. Likewise, we are likely to claim the success of others whom we chose to connect ourselves with.


  • Information from a recognizable figure of authority can provide us with an easy representation of how to act in a situation.
  • Symbols of authority such as titles and clothing act as totems of legitimacy for our automatic behavior patterns. For instance, a nicely dressed man with a long title sounds professional—but he could also be a bum.
  • A great illustration of the power of authority is shown in the movie Catch Me If You Can. Frank Abagnale Jr. maneuver as a pilot, medical doctor, and legal prosecutor all by appearing to have all the qualities of the roles that stereotypically are associated with them.
  • Experts are not experts until proven otherwise. Base the merits of a person or request not on titles or external amenities, but on what has actually been proven. We need to clarify with ourselves that what constitutes as truth is not based creditably via authority.


  • The Rule of the Few: Everything that seems to be less available becomes more desirable.
  • Loss Aversion: Our intuitions take action to protect against losses. So when we are presented information that would lead us to ‘miss out’ on something we are inclined to take action to present the potential loss.
  • We desire banned items. Because our freedom to obtain the item is being limited our desire for ownership increase. One can assume that since it is banned it has substantially more value because of its limited obtainability. For example, banned books tend to be a sought-after commodity in the areas that the item is prohibited.
  • “Deadline technique”: Setting a time-based deadline creates the illusion of urgency. This explains why every store is “going out of business.” The deadline technique is also a very practical way to manipulate our own psychologies. By setting deadlines for our goals, we create the same sense of urgency for completion we would get from a limited product.
  • Psychological Reactance Theory: we respond to the loss of freedoms by desiring them more. This is especially true for social commodities.
    • Cookie Study: Researcher’s presented jars of cookies whose contents had been intentionally lowered by the researchers. The differences in presentation of the scarcity caused different responses. Those who had cookies presented and then removed due to counting error found the cookies to be dull. While the group that was told that the cookies were given away due to demand by others found the cookies to be the some of the best cookies they ever had.
  • The quantity of an item availability often impacts our assumptions on its quality. This holds true in most cases. A good deal is in part good because it is of limited by amount or time.

Interested in learning more? Check out this playlist from the College Info Geek Podcast that discusses each of the 6 Weapons of Influence in depth.

Reading Recommendations

If you liked what you saw. Here are 3 titles that I recommend based on what discussed in Influence.

  1. How to Win Friends & Influence People by Dale Carnegie
  2. Predictably Irrational, The Hidden Forces That Shape Our Decisions by Dan Ariely
  3. Pre-Suasion: A Revolutionary Way to Influence and Persuade by Robert Cialdini

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