Book Notes by Abi Noda

Influence - by Robert Cialdini

ISBN: 006124189X
READ: Feb 14, 2014

Critical Summary

Influence centers around the core question "what are the factors that cause a person to say yes to another person?"

The six "weapons of influence" discussed in this book are:

  1. reciprocity - our need to return gifts and favors, even when they are uninvited
  2. commitment and consistency - our pressure to act in consistency with our past actions
  3. social proof - our tendency to behave as others are behaving, especially in times of uncertainty
  4. affinity - we prefer to say yes to people we like
  5. authority - we unthinkingly obey authority
  6. scarcity - we desire things more when they are less available

Cialdini discusses each of these weapons in-depth, with explanations of what they are, how we develop the underlying behavior patterns that fuel them, and techniques and examples of how to employ and defend against them.

This book contains no fluff. Cialdini's dense but captivating arguments are supported with many great examples and experiments. He is able to dive deep into stories and examples without sacrificing practicality—I left this book with countless insights and applications for both my personal and professional life.

What I found most interesting is that all of the weapons of influence source their power from our natural behavioral tendencies. Like the mating triggers and automatic reactions often found in species of insects, humans also have automatic behaviors that are partly biological, but more often conditioned by society. The paradox of these automatic behavior patterns is that they provide invaluable shortcuts for keeping up with the demands of modern life, but can also lead us to mistakes that can be exploited by outsiders. Furthermore, as the demands of daily life increase, we will increasingly revert to shortcuts for our decision-making without a fully considered analysis, making us increasingly vulnerable to exploitation.

Depending on which side of the wall you're standing on—innocent consumer or preying marketer—this prophecy may concern you or inspire you.

Weapons of Influence

Fixed-action patterns are blindly mechanical patterns of actions that are triggered in specific ways. Fixed-action patterns can be easily observed in nature, eg. mating signals of insects. You will also find organisms that mimic the trigger features of other species in an attempt to exploit them, eg. flies that use the mating signal of another species of fly to lure them close to be eaten.

Humans also have automatic behavior patterns. And just like inspects, the trigger features that activate them can be used by exploiters to dupe us into behaving the way they want us to.

Unlike the mostly instinctive response sequences of nonhumans, our fixed-action patterns usually develop from psychological principles or stereotypes we have learned to accept.

Automatic behavior patterns provide us shortcuts to deal with the vast and complex environment that we live in. Very often in making a decision about someone or something, we don't use all the relevant available information. We instead use only a single, highly representative piece of the total. This tendency can lead us to mistakes that can be explored by others.

Despite their widespread use and importance, most of us know very little about our automatic behavior patterns, perhaps due to the mechanistic, unthinking manner in which they occur.


The paradox of all weapons of influence is that they offer us shortcuts that are invaluable for keeping up with the quickening pulse of modern life. Each weapon of influence, by itself, provides a highly reliable cue as to when we will be better off saying yes than no. We are most likely to use these lone cues when we don't have the time, energy, infliction, or cognitive resources to undertake a complete analysis of the situation. Because technology can evolve much faster than we can, our natural capacity to process information is likely to become increasing inadequate, which reveals another paradox that with our uniquely sophisticated brains, we have built a world so complex, fast-paced, and information-laden that we must increasingly deal with it in the fashion of the animals we long ago transcended. Without the luxury of a fully considered analysis, we will revert increasingly to a focus on a single, usually reliable feature for making our decisions, which in turn makes us more vulnerable to be make mistakes that an be explored by others.

I'm visualizing an image of humans consumers behaving automatically like insects.

Employing weapons of influence is like jiujitsu — not an overpowering act of force, but rather a subtle and sophisticated move that exploits forces that are naturally present. This gives exploiters the ability to manipulate without the appearance of manipulation, and conversely victims the tendency to see their compliance as determined by natural forces rather than by the designs of the person who profits from that compliance.

perceptual contrast principle = when we compare two items, if the second item is different from the first, we tend to see it as more different than it actually is. eg. 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 less attractive than she actually is.



What is it?

Reciprocity is our sense of obligation to others in repayment of favors, gifts, invitations, etc. Most of us find it highly disagreeable to be in a state of obligation. It weighs heavily on us and demands to be removed. Thus the click is a gift or favor, and the whirr is the obligation and act of reciprocating.

How did we develop this fixed-action pattern?

The rule of reciprocity is in the best interests of society as a whole (eg. promotes resource sharing and acts of goodwill). Thus we are conditioned from childhood to abide and believe in it. Reciprocity is pervasive and found across all cultures. And there is a genuine distaste for individuals who fail to conform to the dictates of the reciprocity rule (eg. being labeled a "moocher").

How can it be exploited?

The simple way to exploit reciprocity is to do someone a favor and then later ask for something from them.

Features of reciprocity that make it exploitable:


My banker at Chase is employing reciprocity against me — he's been expunging my ATM fees for me, and now I feel obligated to consider Chase Private Client at his request. Another time reciprocity was exploited against me is when a man came up to me on the street and asked if I needed help with directions (I was lost). I did, so he walked me to the bus stop I was looking for. Once we arrived, he asked for money.

How to Say No

You can prevent yourself from being the victim of the reciprocity rule by recognizing the requestor's action as a compliance device rather than a genuine favor. Once you have identified this, you are free to proceed unhampered by the inappropriately triggered sense of obligation.

Rejection-then-retreat technique

The "rejection-then-retreat" technique increases your chances of having someone agree to your request by first making a request that will most likely be turned down. Provided your first request doesn't seem extreme or unreasonable, and your second request looks like a concession, it should invoke a reciprocal concession in response—compliance with your second request. In negotiations, your goal is to take an initial position that's exaggerated enough to allow for a series of reciprocal concessions that will yield a desirable final offer from the opponent, yet is not so outlandish as to be seen as illegitimate from the start.

This technique employs the rule of reciprocity to make us feel obligated to make a concession when someone has made a concession to us (eg. if we decline a request for something, we may accept a request for a smaller thing), and the perceptual contrast principle, so the second request looks lesser than it actually is relative to the first.

Because the act of concession yields feelings of greater responsibility and satisfaction with the final contract, targets of the rejection-then-retreat technique not only say yes more often, but are also more likely to follow through and volunteer to perform further requests.

I should employ this technique 100% of the time. In fact this recently played out unintentionally during cap table negotiations...


Commitment & Consistency

What is it?

We have a nearly obsessive desire to be (and to appear) consistent with what we have already done or decided. Thus once we have made a choice or taken a stand, we encounter personal and interpersonal pressures to behave consistently with that commitment. The click is commitment, and the whirr is our automatic stubborn consistency with that commitment.


How did we develop this fixed-action pattern?

We are conditioned to value consistency and associate it with personal and intellectual strength, whereas we view inconsistency as an undesirable personality trait associated with indecision, confusion, or being two-faced. Consistency also gives us a shortcut through the density of modern life -- once we've made up our minds about something, we no longer have to think hard about the issue anymore. While consistency is generally good for us, falling in the habit of being automatically so makes us vulnerable to exploiters.

How can it be exploited?

A exploiter can structure their interactions with us so that our own need to be consistent leads directly to their benefit. They can get us to take some action or make some statement that traps us into later compliance through consistency pressures.

I wonder if there's a viable OrangeQC distribution strategy based on this — eg. getting property managers to get commitment from their contractors to improve quality control measures... or to induce this commitment directly... and then following-up with sales protocols.


Foot-in-the-door technique

The foot-in-the-door technique uses a small commitment to manipulate a person's self-image (eg. you can turn prospects into "customers", citizens into "public servants"), and then exploits that person's new self-image to achieve compliance.

Even compliance with a trifling request (eg. signing a petition) can produce a change of attitude and self-image. And, once a person's self-image is altered, all sorts of subtle advantages become available to someone who wants to exploit that new image because people tend to naturally comply with requests that are consistent with their view of themselves so long as that image holds.

Recall that Made to Stick discussed not only appealing to self-interest, but also appealing to self-identity in order to get people to care about our ideas.

An example of this technique is when residents of a town were initially asked by volunteers to accept and display a three-inch "be a safe driver" sign (a trifling request) on their doors. Two weeks later, volunteers asked them to put up a lawn sign and had good compliance. Importantly, this technique worked just as effectively when the first request was related to state beautification, not driver safety at all -- signing the beautification petition changed the view these people had of themselves. They saw themselves as public-spirited citizens who acted on their civic principles.

There is internal pressure to bring self-image into line with action. There is an external pressure to adjust image according to the way others perceive us.

My attitude toward Muay Thai and compliance toward the idea of fighting changed as my self-image changed based on the perceptions and comments of others.

Commitments are most effective in changing a person's self-image and future behavior when they are active, public, and effortful.

active = having customers fill out the sales agreement rather than the salesman makes it far less likely that customers will back out of a purchase

public = public commitments arouse our drive to maintain that position in order to look like a consistent person. the more public a commitment, the more reluctant we will be to change it

I'm interested in learning how Derek Sivers "don't tell people your goals" evidence stacks up against this.

effortful = the more effort that goes into a commitment, the greater its ability to influence the attitudes of the person who made it. eg. hazing - the more trouble and pain a person goes through in order to attain something, the more they value it

I feel a more intimate relationship with the books I've read AFTER I've published written reviews for them. Would this have implications on the net promoter score of Dev Bootcamp? Since we put students through a roller coaster, do they overvalue the experience afterwards?

Commitment is strongest when we take inner responsibility for it. We accept inner responsibility for a behavior when we think we have chosen to perform it in the absence of strong outside pressure such as large rewards or threat.

"This suggests that we should never heavily bribe or threaten our children to do the things we want them to truly believe in."

Lowball/give-it-and-take-it-away-later technique

After making a commitment, people self-generate reasons to justify and support that commitment — a personal commitment builds its own support system.

Thus once small commitments have been made, people create justifications to support the commitment, and, armed with those reasons, are willing to commit themselves further.

lowball or give-it-and-take-it-away-later technique gets someone to commit to an action based on a lowball offer or impossible promise, then later takes the advantage away. in the time since the person has made their decision, they automatically develop a range of new reasons to support the choice they have made, which increases the likelihood of their continued compliance


How to Say No

Listen to your stomach—recognize when we have been trapped into complying with a request we know we don't want to perform -- you can feel it in the pit of our stomachs. stomachs tell us when we are doing something we think is wrong for us. you can fight back by telling the requester exactly what they are doing and point out the absurdity of foolish consistency.

Social Proof

What is it?

The principle of social proof states that one means we use to determine what is correct is to find out what other people think is correct. It applies especially to the way we decide what constitutes correct behavior in a given situation.

How did we develop this fixed-action pattern?

As a rule, we will make fewer mistakes by acting in accord with social evidence than contrary to it—usually, when a lot of people are doing something, it is the right thing to do.

How can it be exploited?

An exploiter can control the behavior of others (or their appearance) to guide the behavior of an individual. Social proof can be engineered.


Conditions under which social proof is most powerful

  1. Social proof is most effective in high volume. It's better to see a lot of other people performing a behavior than just one.

  2. Social proof is most effective in situations of uncertainty. When the situation or environment is unclear or ambiguous and we are unsure of ourselves, we are most likely to look to and accept the actions of others as correct.

    For example: bystanders witnessing a possible emergency are unlikely to help when there are a number of other bystanders present because in the face of uncertainty, the natural tendency is to look around at the actions of others for clues to learn whether the event is or isn't actually an emergency. since everyone else observing the event is likely to be looking for social evidence, too, and because we all prefer to appear poised and unflustered among others, everyone interprets the situation as a nonemergency.

    "pluralistic ignorance" -- the phenomenon of everyone looking to see what everyone else is doing to determine what is right, to the effect that everyone judges the situation inaccurately

    The best defense against this if you find yourself in a potential emergency is to assign specific directions to specific bystanders—do not wait for the crowd to come to their own conclusion.

  3. Social proof is most effective when the behavior we are observing is done by those that are similar to ourselves. The "font-page suicide" phenomenon demonstrates that imitation is stronger the more similar the subject is to the viewer.

    The best leaders are those who know how to arrange group conditions to allow the principle of social proof to work maximally in their favor.

How to Say No

Disengage your autopilot when 1) social proof is being counterfeit (eg. canned laughter, non-genuine testimonials), or 2) social proof is guiding you toward a poor or wrong decision.

Affinity ("Liking")

What is it?

We prefer to say yes to the requests of people we know and like.

How can it be explored?

  1. The bonds between friends can be used by total strangers to get us to comply with their requests


    1. Tupperware parties—even despite hating them, people feel obligated to go and obligated to buy.
    2. Pressing customers for referrals. Each person is approached with the name of a friend "who suggested I call on you". Turning the salesperson away under these circumstances is difficult—it's almost like rejecting the friend.
  2. Compliance practicioners can get us to like us

    Qualities that make us like someone:

    1. physical attractiveness: we automatically assign to good looking people favorable traits like talent, kindness, honesty, intelligence, without being aware that physical attractiveness plays a role in the process. we unconsciously believe "good-looking equals good". research of attractiveness of defendants demonstrates this. a requestor should try to maximize their attractiveness.
    2. similarity: we like people who are similar to us, whether the similarity is in opinions, personality traits, verbal style, background, lifestyle, or appearance. eg. a requestor can dress similarly or claim to have backgrounds and interests similar to ours.
    3. compliments: we are phenomenal suckers for flattery—we tend to believe praise and to like those who provide it. The information that someone fancies us can be a bewitchingly effective device for producing return liking and willing compliance. eg. the worlds greatest car salesman sent all former customers a card that said "I like you"
    4. familiarity: we like things that are familiar to us. out attitude toward something is influenced by the number of times we have been exposed to it in the past. if you print out photos of your face as well as a flipped version of it -- you will prefer the mirror-oriented version that you are used to seeing, where as your friends will like the normal version which they are used to seeing.

      This seems like a good strategy for the about page of a company website

    5. cooperation: cooperating or working on a task conjointly builds bonds. compliance professionals attempt to establish that we and they are working for the same goals. eg. a car salesman who takes our side and "does battle" with his boss to secure us a good deal, or good cop/bad cop interrogation tactics (also employs the perceptual contrast principle)

    6. association: innocent associations with good or bad things influence how people feel about us, unconsciously. eg. people assume we have the same personality traits as our friends; bad weather causes people to dislike the weatherman whereas good weather makes people like them; military courier's being killed for their messages

      "The nature of bad news infects the teller" --Shakespeare

      compliance professionals try to connect themselves or their products with the things we like, even if it isn't a logical connection. e.g. celebrity product endorsements; car models shown with hot models appear faster and more appealing; congressional politicians announce news about federal projects bringing jobs to their state even when they had nothing to do with it; asking for donations over food -- people unconsciously become fonder of the people and things they experience while they are eating. this association is used in clicker training when training dogs -- the clicker becomes associated with the food, acting as a substitute.

      This is why certain business partnerships, even if they are "just for show", may be worthwhile if they create positive associations. The power of association also applies to content marketing, eg. it's best to republish stories with positive qualities or reactions.

      sports fans feel personally diminished by a hometown defeat. all things equal, you root for your own sex, your own culture, your own locality... and what you want to prove is that you are better than there other person. whomever you root for represents you, and when he wins, you win.

      according to the association principle, if we can surround ourselves with success that we are connected with in even a superficial way (for example, place of residence), our public prestige will rise

      just as we publicly trumpet our connections to successful others, we attempt to diminish our connection with unsuccessful people / events

      we purposefully manipulate the visibility of our connections with winners and losers in order to make ourselves look good to anyone who can see these connections. e.g. name-droppers, groupies; author of best doctors in the US got many enraged protests from the wives of physicians

      subtle but simple example: "We're winning" vs "they're losing"

      this is precisely what happens in typical resume-padding. this is why we want to wear shirts bearing logos or messages of thing we admire

How to Say No

Don't try to resist liking. Rather, be sensitive to the feeling that we have come to like something more quickly or more deeply than we would have expected. Once we notice this feeling, we can begin taking the countermeasures as necessary, for example by mentally separating likability from what is being sold or asked of you.

eg. If you are enamored by a girl because she's some celebrity's sister, stop and think.


What is it?

We are strongly and naturally obedient to authority. the click is orders from the authority, and the whirr is our unthinking obedience in following those orders.

Example: hospital staff and patients obeying a physicians directions even when it doesn't make sense

How did we develop this fixed-action pattern?

Systems of authority confer an immense advantage upon a society. consequently, from religion to stories to the classroom, we are trained from birth that obedience to proper authority is right and disobedience is wrong. conforming to the dictates of authority mostly has a genuine practical advantage for us, given that an authority can provide us a shortcut for deciding how to act in a situation because of their greater wisdom and control over our rewards and punishments (eg. parents, teachers). as adults, the same applies to judges, employers, doctors, and government leaders who have superior access to information and power. if makes so much sense to comply with their wishes that we often do so when it makes no sense at all.

Like the other weapons of influence, there is a paradox in that deferring to authority is usually positive automatic behavior, but let loose mindlessly, it can be exploited. The dynamics of influence by authority seem similar to social proof.

How can it be exploited?

Wherever our behaviors are governed by authority in an unthinking manner, compliance professionals can exploit it by creating the appearance of authority using symbols.

For example, drug companies hire actors to play the roles of doctors and speak on behalf of the product.

Symbols of authority:

"If it quacks like a duck, it's a duck."

In research studies people consistently underestimate how they or others would react under the influence of authority.

Authority can also be established through honesty and trust. For example, a waiter who suggests a cheaper and better dish will have won over their table not only as someone who knows the kitchen well, but someone who is on their side.

Establishing oneself as an antiauthority is a much more accessible sales technique than trying to play as an authority. Also recall that anti authorities were mentioned in Made to Stick as a way of establishing credibility

How to Say No

remove its element of surprise -- have a heightened awareness of authority power and recognize how easily authority symbols can be faked. keep your guard up so as to be able to recognize when authority prompting should be resisted. ask yourself "is this authority truly an expert?" and "how truthful can we expect the expert to be here?"


What is it?

opportunities seem more valuable to us when their availability is limited. our typical reaction to scarcity causes physical and emotional agitation that hinders our ability to think and be rational.

For example, interrupting a face-to-face conversation to answer the ring of an unknown caller.

How did we develop this fixed-action pattern?

The concept of potential loss—we are more motivated by the thought of losing something than by the thought of gaining something of equal value, eg. homeowners who are told how much they could lose from inadequate insulation are more likely to insulate their homes than those told how much money they could save; brochures that state benefits in terms of what can be lost by not acting are more effective. Scarcity also naturally occurs in determining the worth we assign things such as baseball cards. The more rare, the more valuable.

Sources of the power of scarcity:

  1. we know that things that are difficult to possess are topically better than things that are easy to possess--therefore we can use an item's availability to help us quickly and correctly decide on its quality. by employing this shortcut, we are usually and efficiently right.
  2. as opportunities become less available, we lose freedoms. we hate to lose freedoms we already have. This desire to preserve our established prerogatives is the centerpiece of psychological reactance theory, which asserts that whenever free choice is limited or threatened, the need to retain our freedoms makes us desire those choices (as well as the goods and services associated with them) significantly more than previously This is similar to autonomy in the SCARF model. Growing scarcity threatens our autonomy.

    examples: "romeo and juliet effect": parental interference in a couple's relationship causes their love to grow stronger; censored information is more desirable AND viewed as more valuable, believable, and significant than if it were non-censored;

How can it be exploited?

Compliance professionals can make us want things by making them appear scarce or exclusive.


Scarcity can also make us believe things that in turn make us want things—the greater the scarcity/exclusivity of information, the more impactful and persuasive it is. For example, if a tip about a stock is noted as being not generally available information, we believe it more.

Ideal conditions for maximizing the power of scarcity:

This is the magic of open-bid auctions. This is also why if you have a crush on a girl, the attraction grows stronger if you notice another guy flirting with her (I've taken advantage of the reverse side of this with my lost cellphone trick).

How to Say No

Recognize the tide of emotional arousal and stop ourselves short. calm ourselves and regain our rational perspectives. remember that true joy comes from experiencing a commodity, not possessing it. scarcity only increases our desire to possess, not the merits of actually possessing it.