Influence By Robert Cialdini: Summary (6 Principles)

Influence Cialdini book cover

Influence (1984) was the first book on persuasion from an actual psychologist, to go mainstream and top the best-selling charts. In this classic on persuasion, author Robert Cialdini lists 6 principles of influence that make people act.

Exec Summary

  • There are six main principles of influencing: consistency, reciprocation, social proof, authority, and liking.
  • The principles leverage innate switches in our mind: they can be difficult to resist and recognize
  • The switches in our minds often make our life easier with quicker decisions but they can be exploited

Influence Summary

Cialdini says that while there are thousands of tactics that influence practitioners’ use, the majority fall into 6 basic categories.

Each category has a fundamental psychological principle behind it, and “Influence” is organized around these six basic categories.

The 6 influencing principles are:

  1. reciprocity
  2. commitment
  3. authority
  4. social proof
  5. scarcity
  6. liking

1. Weapons of Influence

Cialdini opens the book with a few examples of influence and “triggers” of influence.

The now famous copy machine experiments (full PDF here), for example, are based on a single-word trigger: “because”.


excuse me I have five pages, may I use the machine because I’m in a rush?

had 94% compliance.

“Excuse me I have five pages, may I use the machine?

had 60% of compliance.

You might think the difference is “being in a rush”.
Instead, it was the word “because”.

Asking indeed:

excuse me I have five pages, may I use the machine because I have to make some copies?”

Had 93% compliance.

Simple Minds For A Complex World

Cialdini also tells us of a jewelry store that was only able to sell unsold merchandise when they doubled the price by mistake instead of halving them.

And he tells us of turkeys acting either aggressively or nurturing depending on which chirp was played.
The turkeys don’t act based on all that is real, but only a tiny portion of reality.
In this case, the chirp.

While the stories might seem unconnected, Cialdini says they stem from the same system complexity reduction we deploy.
In many ways, we humans also have pre-programmed tapes.

They usually work to our advantage, but they can be used to dupe us.
The people buying jewelry at double the price, for example, used the shortcut of “price=quality”, even when it was blatantly not the case.

2. Reciprocation

A university professor once tried a little experiment: he sent Christmas cards to perfect strangers.
He didn’t expect many cards back, but they just kept pouring in.

Cialdini says it’s a clear example of Reciprocation.

Reciprocity overwhelms the feeling of liking or not liking someone. We are indeed as much more likely to give back to someone we dislike than to someone we like.

Hare Krishna at airports

Hare Krishna activists used to give travelers a flower as a gift, not accept it back and then ask for a donation.

Most people didn’t want a flower, didn’t like the person, and yet would feel obliged to give back.
It’s indeed the obligation to receive that makes the rule so effective and easy to exploit.

The Hare Krishna, for example, got money, which they wanted, for flowers, which travelers didn’t want.

Other interesting examples of reciprocation are:

  • Carter’s problems as an outsider

Carter had trouble in passing legislation because he campaigned as an outsider who was indebted to nobody in Capitol Hill.
Well, nobody felt indebted to him either when he got to the office.

  • Free samples

is another great way for companies to induce us to buy with the law of reciprocation.

  • Buying drinks for dates

Women often comment on the uncomfortable feeling of indebtedness from men who bought them an expensive present or dinner.

Even a drink can be enough to trigger reciprocity feelings.

Concessions and the Rejection and Retreat Technique

A major consequence of the reciprocity rule is the obligation to make concessions to someone who’s given a concession to us.

Cialdini tells us this is often exploited with the “Rejection and Retreat Technique”.

The technique works by making a big initial request which will be turned down. Then you make the second request which is the one you really wanted to go for all along.

Your retreat and the smaller second request are perceived as a concession, and the receiver will feel like he should now concede back -by moving from “no” to “yes”-.

The larger the initial request -up to a certain point- the more likely the concession will be.

It is often employed to ask for a referral after a refusal.
For example:

Sneaky Salesman: OK this widget is not right for you at this time but perhaps you could help by giving me the name of some others who could take advantage of our great offer

One might guess that people feel cheated by the Rejection and Retreat Technique and they would back out of the deal.
But the opposite is actually true.
It proved indeed to be more effective in having people carry out the request and in performing future similar requests.

It’s because, Cialdini says, people feel more part of the agreement.
They feel like they produced the concessions and influenced the outcome. So they feel more responsible for the outcome.

Reciprocation is a crucial component of social dynamics and effective social strategies, for which we highly recommend this article:

Social Exchange Theory: 5 Laws of Social Success

Preventing Manipulation

Cialdini says the moment you realize there’s a trick behind the initial gift you can redefine the gift as a sales tactic and free yourself from the reciprocity rule used as manipulation.

Manipulation: Techniques, Strategies, & Ethics

3. Commitment and Consistency

The principle of commitment and consistency is that of aligning actions, feelings, values, and beliefs.

When actions and feelings are dis-aligned for example we feel cognitive dissonance (Festinger, 1957), which is a sensation of mental discomfort.

In that case, we might change our beliefs to justify our actions, or we will rationalize our actions in a way that will make us feel “good” about ourselves (more on rationalization in Incognito).

People who bet on a horse, for example, feel immediately more self-assured that their bet will pay off.
It’s because once the commitment has taken place the need for consistency pressures us to bring our feelings and belief in line with the commitment.

Meaning: we convince ourselves we have done the right choice.

The Scrounging Boyfriend

Cialdini also gives us a juicy example of her neighbor Sara.

Sara lived with Tim, a drinking boyfriend who didn’t wanna marry.
Sara broke their relationship and got engaged to an ex-boyfriend.

Tim called Sara before her wedding and promised he would change. Sara stopped the wedding and took Tim back.
Then proceeded to renege on his promises: didn’t stop drinking and still didn’t marry her.

But Sara is more devoted to Tim than she ever was and says she did the right choice.

“How Are You” Manipulation

Solicitors asking for donations might ask you “how are you” first to make you admit you’re doing fine.

After you state aloud you’re good, it’s then easier to corner you into aiding those who are not as well as you are. The solicitor would say something like

Manipulator: “I’m glad to hear you are well, because I’m calling to see if you’d be willing to make a donation for the unfortunate victims of X for whom things are not going too well”.

Research by Daniel Howard showed an 18% agreement among people who asked if they’d be willing to help the hunger relief program.

But after asking “how are you feeling this evening” the percentage jumped to 32%.

The Foot in the Door Technique & Self Image


The foot-in-the-door technique uses the Commitment and Consistency principle by starting small and then asking for more after the initial commitment has been done.

Freedman and Fraser asked homeowners to install a big “drive carefully” billboard on their front lawns. 83% refused.

But when a different group was asked to put up a small 8cm sign and then asked for the billboard, 76% agreed.

Astoundingly another group agreed 50% of the time after they had signed a simple petition to “keep California beautiful”.

Why would they accept a huge billboard after having signed a petition which was not even connected to driving safety?

It’s because these people changed the way they looked at themselves: they started viewing themselves as active citizens acting in the public interest.

So when they were asked later to install a huge billboard to (hopefully) help bring down road accidents they complied to stay consistent with their newly formed self-image.

Cialdini says that this finding made him wary of signing any petition because of the potential to influence future behavior and self-image in ways he might not want.

The Low-Ball

The Low-Ball technique exploits the Commitment and Consistency rule by offering a very low price to get an initial commitment.

Later on in the process, the seller would say there was a mistake and the price is now higher.

But by the time the prospect has arranged financing, and filled out the forms, maybe he’s already driven the car, imagined himself owning it, and convinced himself it was the best decision.
The decision stands on so many legs that removing the price leg is not likely to change his mind.

This is the same that happened to Sara in accepting her drinking BF back.

She got a great offer at the beginning and accepted it.
And after Tim didn’t marry her and didn’t stop drinking Sara had built in her mind so many other advantages about Tim that she was happy anyway.

Actions Only Matter: The Chinese Brainwashing

People look at actions to determine personalities more than words.

The Chinese in their efforts to convert POWs to communism realized that we also look at our own actions to assess who we are.

So the Chinese built up from small actions to bigger and bigger commitments until they’d bring about full conversion to the communist ideology.

The Chinese would also make public what an individual had done, written, or signed.
And since what those around us think is true of us influences our actions and what we think is true, POWs also had social pressure to embrace the communist ideology.

It’s a lengthy part of Cialdini’s book and I have given you the main and most important gist.

Written Statements Increase Compliance

Written statements are a powerful way of spurring our sense of Commitment and Consistency.

Cialdini tells us that companies employing hard sales critiques experienced high cancellation rates.

And what was their way to reduce cancellations drastically?

Letting their customers write down their own orders.

Now the buyers cared less they have been pushed and cajoled into buying and focused more on their own commitment.
And of course, the effort they had put into writing it also added (a bit of) sunk costs to the interaction.

That’s why it’s so important to write down our goals.

Effort Increases Commitment

People who spend a lot of effort to obtain something tend to value it more highly than if it had been very easy to obtain it.

Cialdini says that’s the reason why so many groups have hazing and initiation procedures: making it difficult to enter a group makes the group more valuable (also read: office power moves).

Indeed tribes with the most dramatic initiation ceremonies also tended to have the highest group solidarity.

Similarly, you are usually well served in giving small or no incentive for the behavior you want to encourage.
People who had no major incentive feel like they chose and will accept more responsibility.
This is the same principle of Intrinsic Motivation from Daniel Pink’s Drive.

On the same note you don’t want to impose threats to direct the behavior of your children, but rather have a reason that will produce the initial desired behavior and have the child take personal responsibility for it (also read How to Talk So Kids Will Listen).

Commitment Makes Us Take More Risks

An experiment on a beach showed the power of Commitment and Consistency even with the possibility of personal harm.

Researcher 1 left his radio near to take a stroll and Researcher 2 stole it pretending it to be a thief.
Only 4 out of 20 people it was tried on to stop him.

But when Researcher 1 asked to “please watch his things” 19 of the 20 people it was tried on became ran after the thief.

Why Commitment and Consistency Works

Cialdini says the Commitment and Consistency principle works because it’s valuable and adaptive.

Consistency is another way to reduce complexity and mental load by offering a shortcut.
You commit to something and don’t have to think about it anymore.

Inconsistency instead raises our mental load and is commonly thought to be an undesirable trait.

Overcoming Commitment and Consistency Tricks

Cialdini says you will likely feel a knot when you’re being tricked with Commitment and Consistency tactics.
What you do then is to tell them exactly what they’re doing to you.

He recounts a brilliantly funny story of a woman in a short skirt who employed the Commitment and Consistency tactic on him.
He fell straight into it and exaggerated how many times he’d go out for restaurants and movie nights to appear like a socialite.

In the end, when the woman told him she had the perfect card to save him money, he had no place to hide. He admitted and committed to his answers; now he had to stay consistent to save face.

Cialdini says that if the same were to happen today he would tell her she was chosen for the job for her physical attractiveness, that men would exaggerate to prove what great swingers they are, and that he would not buy her club membership.

Some other times when our decisions have already grown legs we won’t feel anything in our stomach. In those cases, we ought to ask ourselves this question: “knowing what I now know, if I could go back in time, would I make the same choice?”.

Cialdini says that in a split second before our rational mind takes over, we will get a real feeling about our choice.

Control your behavior: it determines who you are

4. Social Proof

Nobody likes canned laughter.

But they work.

Canned laughter makes us laugh longer and harder.
The difference is especially great with poor-quality jokes. Cialdini says it works because we get the feeling other people like it.

That’s social proof.

What other people think and do is one of the ways we use to find out what’s correct.

Cialdini says that since 95% of people are imitators and only 5% of initiators people are swayed more by the action of others than any proof we can offer.

Pluralistic Ignorance and Letting People Die

Cialdini draws attention to a highly publicized instance in which a woman was let die without help, in spite of many having heard her screaming.
It happens for two reasons:

  1. “Distributed responsibility”, such as the more people around the less each single one feels responsible
  2. We’re not always sure if an emergency is always an emergency and that’s when we look at how other people react to assess the situation.

When nobody reacts it’s a sort of Spiral of Silence situation where everybody is taking everyone’s inaction as a cue they shouldn’t act either. This phenomenon is called Pluralistic Ignorance.

An experiment found indeed that a researcher faking a seizure received help 85% of the time when there was a single bystander and 31% with five bystanders.

Similar experiments have been repeated with similar results.
In Canada, a single bystander provided help 90% of the time and 16% of the time when 3 people were presented and 2 researchers purposefully remained inactive.

Basically, people don’t help when they’re unsure if it’s an emergency and when they’re unsure if it’s their responsibility.

The safety in number then can sometimes be a completely mistaken idea and Cialdini suggests you make sure people know it’s an emergency by shouting for help and pointing at someone.

Social Proof From Those Like Us

Social proof affects us most when the people around us are somewhat similar to us.
When jaywalking we are more likely to follow up with people similarly dressed to us for example

And it works in nefarious ways too: homicide rates have a strong copycat effect.
In highly publicized fight matches when a black fighter lost black homicide victims rose. When it was a white fighter who lost the number of homicide victims increased for white men.

5. Liking

We prefer to say yes to the requests of someone we like.

Cialdini talks about the now (in)famous Tupperware parties as an example.
And he and says that referrals are a way of exploiting the Liking principle.

These are the principles that make us like someone:

Physical Attractiveness

We assign good-looking individuals characteristics such as talent, kindness, honesty, and intelligence.

Attractive people are voted more, receive more money in compensation, get hired more, and are twice as likely to avoid prison sentences.
And, interestingly enough, most people are little nor aware at all that their decisions have been swayed by physical attractiveness.

Similarity Influences People

We like people who are similar to us. People who have similar backgrounds and interests, but also similar names.

And we are also more likely to help those who dress like us, and we’re more likely to sign petitions from them without even reading them.

We need to be careful when we feel a bit too close to a salesperson because many sales programs teach us to mirror and underline similarities.

Praise Influences People

We love flattery and albeit we might know the flatterer has second motives we tend to believe praise anyway and we tend to like those who provide them even when the praise is false.

How Associations Influence Us

People have a natural tendency to associate us with the news we bring even when we’re not responsible for that news.

Positive news = positive association;
negative news = negative association.

Weather forecast announcers have received death threats when the rain didn’t stop or tornadoes threatened to hit.

We are also associated with the crowd we hang out with and people do assume we have the same personality traits as our friends.

Advertisers using models for their cars want to associate beauty and desirability with their cars. And it often does work.
Young men looking at cars with a model nearby rated it as faster, more appealing, and more expensive than the same ad without a model.

Again this is something that works unconsciously, and people weren’t aware it was happening.

Similar is the case of linking celebrities to products.
Cialdini says the association doesn’t even have to be relevant, just positive.

And Gregory Razran found out what has been named the “Luncheon Technique”: people became fonder of what or who they experienced while eating.
Razran presented several political statements while and while not eating. Only the ones shown during eating gained approval.

Association and Sportsfan

Cialdini explains the phenomenon of sports-fan via the association principle.

We associate with a sports club and then want them to win to prove our own superiority. People feel their success will somehow raise their own social prestige.

Research proved indeed that after a team had won the pronoun “we” was used and the same pronoun was instead avoided when the team lost.

What I was even more impressed to hear though was that people who had done well in a test didn’t change much the use of the pronoun “we” when discussing their team whether the team had lost or won (24% vs 25%).
But those who had done poorly in a test had a much bigger drive to associate themselves with a winning team (17% vs 41%).

It’s indeed people low on the feeling of personal accomplishment that seek compensation through their teams.

Cialdini says it’s similar for name-droppers and groupies. It’s the same drive of seeking accomplishment outside of ourselves.

6. Authority

Cialdini mentions the now-famous Milgram’s Obedience Study.

Under the insistence of the researcher -the authority- 65% of participants kept administering excruciatingly painful electric shocks until the maximum level.

It is widely acknowledged that the reason people kept going is that the authority figure kept insisting.

The Doctor & The Rear

Another example from Influence has probably had thousands of people laughing the whole world over.

A typical authority figure is a doctor.

A doctor left a note for the nurse on how to cure a patient’s ear infection. A right ear infection, to be precise.
The note said to administer the ear drops in abbreviate form.

Such as: “place in r(right) ear”.
The nurse administered the ear drops in the anus. Neither she nor the patient said anything.

Similarly, an experiment showed how nurses followed a doctor’s directive via phone and started preparing a dose of medication that would have been lethal.

Very few objected.

If you are incredulous, keep in mind that the behavior and demeanor of the authority figure are other important indicators of the likelihood that people will execute orders without reproach.

In Instant Influence, Pantalon tells us that it’s mostly authoritative bosses who go unchallenged.

Why Authority Works

Authority works because, like most other psychological triggers, it has several practical advantages for us.

It made sense to listen to authorities like parents and teachers.
They both knew better and held control of our rewards and punishments.

How Titles Influence Us

The appearance of authority is all it takes: we are as affected by the actual authority as by the symbols of authority. And a title is often all that it takes.

Cialdini says that titles are hence very popular among people short in substance.

Prestigious titles lead people to assess the title holder as taller. In an experiment, the title “professor” instead of “student” lead to an increased height perfection of 2.5 inches (10+ cm).

It’s actually a rather general tendency to link size to importance.
We also estimate more expensive cars as bigger. And estimate higher-value coins as larger.

Cialdini says it’s one of the reasons why conmen wear lifts in their shoes.

Uniforms Influence Us

Uniforms are another major symbol of authority.

And so are suits.

People jaywalking in a suit are more likely to be followed by bystanders than people dressed in casual clothes.

Status Symbols

Owners of prestigious cars receive special treatment.

People wait significantly longer to honk when it’s a luxury car stopping in front of their car.
The opposite was true for cheaper models.

Funny enough, students asked what they would do in such a situation, especially men, who said they’d honk quicker to luxury cars (again: action matters, words don’t).

It’s similar to other popular status symbols such as expensive golden jewelry, diamond rings, and furs.

Defending from Authority Influence

We constantly underestimate the power of authority influence.

But Cialdini says that we naturally trust impartial authorities more than the ones who have something to gain from convincing us.

A trick from compliance professionals is to criticize their product on a minor detail to gain our trust and then move to major positive traits. You can be more on the lookout when this technique is used against you.

Cialdini then gives us a great example of a successful waiter using that technique (get the book for the description).

7. Scarcity

We tend to want more of what’s scarce.

Scarcity, New Scarcity & Demand Scarcity

A famous experiment of supply and demand on product ratings gave to 200 undergrads a jar with 2 cookies and a jar with 10 cookies.

The cookies from the small jar were rated higher, more pleasurable to eat in the future and even higher estimated value.

A second experiment gave a jar of 10 cookies, a jar of 2 cookies, and a jar of 10 cookies then replaced by a jar of 2.
The swapped 2 cookies jar was the highest rated. Indeed we want most what has become scarcer rather than what has always been scarce.

A third experiment shows that cookies that became scarce because of social demand were rated the highest of all.
The sub-communication, in this case, is that we are in competition for a scarce resource.

Salespeople exploit this principle all the time with fabricated demand and competition.
And it’s even used in the romantic arena when women (or men) want to make us jealous by showing off pursuers.

Scarcity Explains Revolutions

Cialdini says that revolutions are more like to happen when people have been given a taste of a better life.

Going from high to low, from happy to sad, usually, feel worse than if we had never had the good times.

That means that for despots, it’s more dangerous to give and take some away later on than never to give anything at all.

And people are more motivated by the thought of losing something than gaining something.
Homeowners pitched on how much money they’re losing without insulation are more likely to get insulation than those told how much money they can make.

Defending from Scarcity

Cialdini says that when we feel the competition urge we should stop, get rational again, assess why and how we really want the item and set a maximum price we are willing to spend.


Cialdini says that in an increasingly complex and fast-paced world, we need shortcuts to make decisions.

And that is exactly why we have the moral obligation to rebel and push back on any attempt to trick us with influence shortcuts.

In a way, The Power Moves is doing exactly what Cialdini is advocating.

Influence Cialdini book cover

Real-Life Applications

The whole book is about practical application, but I wanna tell you one thing which was important in my development:

  • Stop Supporting Anyone to Feel a Winner

I used to be either furious or ecstatic about any failure or victory of my favorite team or sportsperson.

I had to reprogram myself.

One is because you are giving up control of your feelings.
And two, because you might be compensating for your own lack of self-esteem and success.

Support this or that sportsperson, but don’t let it get to you, and don’t use it for compensation.

Influence Video-Summary

Influence Criticism

  • Brainwashing Effectiveness

Some sources criticize the effectiveness of the Brainwashing methods” –Brainwashing was bunk”, NYT– but the techniques certainly can influence people.

In a nutshell: brainwashing works best with people with a confused identity, a sense of guilt and with black and white thinking.

  • Tupperware and Referrals = Like Principle?

Cialdini lists the Tupperware sales technique and referrals as examples of the Liking principle.

But I think he’s wrong there.

These are examples of social obligations.
Cialdini himself tells us of a woman complaining about the invitation to yet another Tupperware party.

She didn’t want to go. And at that point, I doubt she liked the host. But she felt the obligation to.


Influence is a seminal book on soft power and a mandatory book in your quest of becoming a better influencer. 

It’s well-researched, well-structured, and well-written.

As a last important note, Cialdini says that none of the weapons of Influence is so strong as to work on everyone at all times.

Get Influence on Amazon.

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