Influence

By Robert Cialdini

Book Overview

Ever found yourself buying something not really worth the price, or signing up for a service you didn’t need, just because someone convinced you? If so, you’re not alone. It happens to all of us. The truth is, you've likely been influenced by a "compliance professional"—someone skilled at getting people to agree to their requests.

Robert B. Cialdini, the author of Influence: The Psychology of Persuasion, knows this feeling all too well. Feeling like he was always an easy target for manipulation, he spent years studying why people comply with others. Through experiments, interviews, and observing persuasive professionals, he identified six key principles that explain how people are influenced.

These principles are:

• Reciprocity: the need to return a favor.

• Commitment and consistency: the desire to align with what we’ve previously said or done.

• Social proof: following others’ actions.

• Liking: being persuaded by people we like.

• Authority: trusting experts.

• Scarcity: wanting something because it’s limited.

Understanding these techniques can help you spot when someone is trying to manipulate you—and can also help you become more persuasive if that’s your goal. You’ll learn tricks like how simple words can get you ahead in line, why you should be cautious when someone offers unsolicited help, and how powerful influence can even turn sunbathers into activists.

The Power of Mental Shortcuts and How We Get Tricked

Turkey mothers are caring and protective, but their love depends on a single thing: the “cheep-cheep” sound from their chicks. If a chick makes this sound, the mother nurtures it. If not, she may ignore or even harm it. Shockingly, even a stuffed predator, like a polecat, can get the same loving care from the turkey if it makes the right noise.

This shortcut may seem strange, but humans rely on similar shortcuts every day. The world is too complicated to think deeply about every decision, so we use these quick rules to help us. Most of the time, they work well.

For example, we are more likely to do someone a favor if they give us a reason. In an experiment, a researcher asked people if she could skip ahead in line at a copy machine. When she gave a reason—“because I’m in a rush”—94% agreed. Surprisingly, even when she used a silly reason—“because I need to make copies”—93% still let her cut the line. Just hearing a reason was enough.

But these shortcuts can also be used against us. Compliance professionals, like salespeople or advertisers, know how to trick us into making choices that benefit them. One common shortcut is the idea that “expensive means better.” Some stores raise prices on unsold items because people assume a higher price means better quality.

To avoid being fooled like the turkey, we need to recognize these mental shortcuts and defend ourselves from those who use them against us. The next sections will explain six key shortcuts—reciprocation, scarcity, consistency, social proof, liking, and authority—that shape our decisions and how they can be used to influence us.

“A well-known principle of human behavior says that when we ask someone to do us a favor we will be more successful if we provide a reason. People simply like to have reasons for what they do.”

The Hidden Power of Favors and How to Spot Them

Have you ever accepted a free flower or a sample on the street? Or maybe a waiter brought you a sweet treat with the bill? These kind gestures may seem innocent, but they’re actually a clever way to influence your actions.

The rule of reciprocation, the first principle of persuasion, makes us feel like we need to return favors. This instinct helped our ancestors build trust by sharing resources, knowing they’d get help later. But today, people sometimes use this rule to manipulate us.

For example, if someone gives you something small, like a free sample, you may feel obligated to give something back. A famous study showed this: a man named Joe bought people a ten-cent Coke, and later asked them to buy raffle tickets. Those who got the Coke spent 50 cents on tickets, even if they didn’t like Joe!

This shows how strong the urge to return a favor can be, and it’s not limited to personal interactions. Even countries act on this rule: in 1985, poor Ethiopia sent money to Mexico after an earthquake. Why? Because Mexico had helped Ethiopia in 1935 during an invasion.

Religious groups, like the Krishnas in the 1970s, also used this tactic. They gave flowers to strangers, who then felt pressured to donate money. People felt the need to give something back, even if they were annoyed.

So how can you avoid falling into this trap? Start by asking yourself if a favor is genuine or just a trick to get you to do something. If you realize it’s manipulation, remember: tricks don’t deserve your kindness in return. Save your goodwill for true acts of generosity.

The Power of the Rejection-Then-Retreat Strategy

The rejection-then-retreat strategy is a powerful negotiation tactic that takes advantage of our desire to return favors. This technique involves starting with a large request that is likely to be turned down, then making a smaller request, which seems more reasonable in comparison. When someone makes a concession, like reducing their request, we feel compelled to reciprocate.

The author shares a personal story to illustrate this. A Boy Scout tried to sell him a five-dollar ticket to a circus. After he refused, the Scout offered chocolate bars for a dollar each instead. Feeling obligated to respond to the Scout's concession, the author ended up buying two chocolate bars. This response was influenced by the contrast principle, which makes the second option seem much cheaper when compared to the first.

In negotiations, starting with an unreasonable demand can make your actual goal seem more acceptable. Labor negotiators often use this strategy to gain concessions. However, there is a limit to how extreme your initial offer can be. If it’s too outrageous, it may backfire, and people won’t feel obligated to reciprocate.

The author also cites a historical example involving G. Gordon Liddy during the Watergate scandal. Liddy proposed a million-dollar scheme that included extreme actions. When he later suggested a less outrageous plan for 250,000 dollars, it seemed more acceptable due to the initial outrageous proposal. Ultimately, this strategy contributed to a major political scandal that led to President Nixon’s resignation.

The Impact of Scarcity on Our Decisions

Advertisers frequently use phrases like “limited time only” and “last chance” to grab our attention because of the scarcity principle. This principle suggests that when something is hard to get, we want it more. People tend to view items as more valuable if they are in limited supply, mainly because we dislike missing out on opportunities.

A study conducted in 1982 demonstrated this effect. Shoppers who were informed about a limited-time sale on meat bought three times more than those who didn’t know about the time limit. When customers were also told that only a few people knew about the sale, they purchased six times more. This shows that both the scarcity of the offer and the exclusive information can significantly boost sales.

Two main conditions enhance the influence of scarcity on our choices. First, we desire something more when its availability suddenly decreases rather than when it has always been low. For example, revolutions often happen when living conditions worsen quickly, pushing people to seek change. Second, competition fuels our desire. When we think someone else might get what we want, we often become overly eager. Real estate agents often create a sense of competition by claiming multiple bidders are interested in a property.

A notable example is Barry Diller, an ABC executive who paid a record 3.3 million dollars for the rights to show a movie just once. This occurred during an open-bid auction where everyone could see each other’s bids, leading to a bidding war driven by competition.

To avoid being swayed by scarcity, we should consider whether we truly want an item for its usefulness or simply out of a desire to possess it. Often, the urgency created by scarcity influences our choices more than the item’s actual value.

“people seem to be more motivated by the thought of losing something than by the thought of gaining something of equal value.”

People Desire What They Cannot Have

The saying that people want what they can’t have holds some truth. This is often seen in children; when a toy is forbidden, it suddenly becomes much more appealing. This phenomenon extends to adults as well, especially regarding censorship. When information is banned, it seems more valuable than if it were openly accessible.

For instance, a study from the 1970s at the University of North Carolina showed that when students learned about a canceled speech against co-ed dorms, they became more supportive of the idea, even without hearing the speech. This shows how censoring information can actually increase interest.

This effect can also be seen in legal situations. Research indicates that juries tend to award larger damages when they know an insurance company will cover costs. Interestingly, when judges tell juries to ignore the defendant’s insurance, the juries often award even higher damages. This “forbidden” information makes the juries react more strongly, similar to how children desire a forbidden toy.

An example from Dade County, Florida, illustrates this well. When the county banned phosphate-based laundry detergents, residents started to hoard them and viewed them as better than before.

This longing for what is restricted is called the Romeo and Juliet effect, named after the famous story of star-crossed lovers. When parents try to block their children’s relationships, it often makes the lovers feel more attracted to each other. A study of couples in Colorado showed that parental interference strengthened their feelings of love, while reducing interference caused those feelings to fade.

“The way to love anything is to realize that it might be lost.”

Small Requests Can Influence Our Decisions More Than We Think

Picture yourself relaxing at the beach, eager to take a refreshing swim but concerned about your belongings. A study by psychologist Thomas Moriarty highlights the benefits of asking someone nearby to keep an eye on your things. When people saw a staged theft of a radio from a towel, only 20 percent reacted. However, if the owner asked their neighbors for help, 95 percent jumped into action, even risking their safety to chase down the thief.

This strong response is linked to our desire for consistency. We want our actions to align with our words. This need for consistency can sometimes override our personal safety concerns. By being consistent, we make our lives easier because we don’t have to constantly decide how to react; we can simply follow our previous choices.

Commitment is the key factor that drives this consistency. Research shows that once we make a commitment, we feel compelled to stay true to it. Public commitments are particularly effective.

For instance, during the Korean War, Chinese interrogators influenced American prisoners by asking them to make small, harmless concessions, such as writing statements like “America is not perfect.” When these statements were made public, the prisoners began to view themselves as collaborators, aligning their self-image with what they had written. The act of writing down their commitment made it feel more real and significant.

Salespeople often use the foot-in-the-door technique to take advantage of this idea. They start by asking for a small purchase, creating a commitment in the buyer’s mind. This shift in self-image makes the customer more willing to consider larger purchases later. So, the next time a salesperson makes a small request, think carefully about how it might affect your decisions.

The More Effort We Put Into Something, the More We Appreciate It

Initiation rituals frequently involve pain and humiliation, from African tribes to college fraternities. Despite attempts to put an end to these practices, they continue. Why do these groups uphold such traditions? The answer is straightforward: when individuals put in significant effort to become part of a group, they place a higher value on their membership. The struggle for acceptance deepens their commitment to the group.

Interestingly, fraternities often resist changing initiation rituals to community service tasks, like helping in hospitals. They want members to willingly choose to endure the degrading rituals instead of feeling like they did it for a good cause. This inner choice encourages members to see the group as more valuable, leading to a stronger commitment.

Research shows that decisions based on personal choice create lasting change more effectively than those made under external pressure. For example, salespeople use tactics like the lowball trick to create this inner change. A car dealer might initially offer a car at a very low price. Once the buyer is excited and decides to purchase it, the dealer retracts the offer with an excuse and raises the price. Buyers often still go through with the purchase because they create new reasons to justify their decision, like the car’s color or fuel efficiency.

To avoid falling into this trap, it’s essential to ask yourself if you would have made the purchase if you had known the true price upfront. If the answer is no, it’s best to walk away. This approach can help protect you from being manipulated into valuing something more than it’s worth.

We Are More Likely to Act When Others Do

Sitcoms often include laugh tracks because they can make us laugh longer and more frequently, even at jokes that aren’t particularly good. This happens due to social proof, which is the idea that we often look to others to guide our actions. When we hear laughter, even if it’s artificial, it indicates that others find the jokes funny, encouraging us to feel the same way.

This idea of social proof is also used in other situations. For example, church ushers might place a few bills in collection baskets before a service to make it look like many people are donating. Companies advertise products as “best-selling” or “fastest-growing” to suggest that others are buying them, which encourages more customers to join in.

Social proof has a strong effect when we are unsure what to do. A famous example is the case of Kitty Genovese, who was murdered in 1964 outside her New York apartment. Some neighbors heard her cries for help but did not intervene. The media criticized them for being uncaring. Later studies showed that some neighbors did try to help, but the case highlights the “bystander effect.” This means that when many people are around, individuals feel less responsible to act, thinking someone else will.

In emergencies, it’s hard to know what’s really happening. For instance, a person on the street might need help, or they could just be drunk. In uncertain situations, people often look to others for cues on how to respond. To get help in an emergency, it's best to focus on one person in the crowd and directly ask for help. For example, saying, “You in the green shirt, call an ambulance,” makes it clear that they need to act.

“Since 95 percent of the people are imitators and only 5 percent initiators, people are persuaded more by the actions of others than by any proof we can offer.”

We Often Imitate Others, Even in Tragic Ways

People frequently look to others for guidance on how to act, especially when those individuals are similar to them. This is particularly evident in teenagers, who often follow the opinions and fashion choices of their peers. Unfortunately, this tendency can lead to troubling consequences. For instance, when a suicide receives a lot of media attention, the number of accidental deaths in plane and car crashes tends to rise in the following week.

This strange trend can be explained by the fact that some individuals may choose to end their own lives in a way that looks like an accident after being influenced by the highly publicized suicide. Research shows that these are not individuals who were already contemplating suicide; instead, a single front-page story about a suicide can lead to approximately 58 additional deaths that would not have occurred otherwise. This phenomenon is known as the Werther effect, named after a book from the 18th century that led to a wave of suicides among readers.

The Werther effect is especially strong among people similar in age to the person who died by suicide. For instance, young people are more likely to be affected by reports of young suicides, while older individuals may respond more to stories involving seniors.

In a different context, marketers often use fake interviews with “regular people” to promote their products, knowing that endorsements from people who seem relatable can have a strong influence. To protect yourself from being misled by such tactics, it’s essential to stay aware of counterfeit social proof and avoid products from companies that manipulate consumers through false endorsements.

Tupperware Parties Show How We Get Influenced by Others

Tupperware parties are a clever way to get people to buy products, and they use several smart tricks. When you attend a party, you often get a gift, which makes you feel grateful and more likely to buy something. This is known as reciprocity. Also, when you see others making purchases, it influences you to buy too, thanks to social proof. It creates the idea that if others are buying it, you should too.

What makes Tupperware parties even more effective is that a friend, someone you like, invites you instead of the salesperson. We generally follow the requests of people we enjoy spending time with.

Salespeople also know how to make you like them. They often compliment you or point out similarities between you and them, which makes them more appealing. For example, a salesperson might say, “That tie is great! Blue is my favorite color too!”

Another reason we tend to like people is attractiveness. People who are good-looking are often seen as nicer and smarter, which can even affect who we vote for in elections.

Cooperation can also build likability. For instance, in the good cop/bad cop method, the good cop makes the suspect feel like they are on the same team, making them more likely to confess.

Additionally, we connect our feelings with people based on experiences. For example, if you hear good news while enjoying a tasty meal, you associate that good news with those happy feelings.

To avoid being manipulated by likability, think about whether you suddenly like someone a lot in a short time. If you do, it might be a sign that you are being influenced, so it's good to be cautious.

“We like people who are similar to us. This fact seems to hold true whether the similarity is in the area of opinions, personality traits, background, or life-style.”

The Influence of Authority on Our Decisions and Actions

From a young age, we learn to follow authority figures like teachers, doctors, and police officers without questioning them. This habit is so strong that we often don’t think for ourselves when we’re told to do something by someone in charge.

In the 1960s, psychologist Stanley Milgram ran an experiment showing how people would give dangerous electric shocks to others just because an authority figure told them to. Even though no one was really harmed, the results surprised everyone involved.

Another example is a nurse who, given instructions from a doctor to treat a patient’s earache, ended up putting drops in the wrong place because she didn’t stop to question the orders. This shows how authority can stop us from thinking critically.

We also tend to trust authority based on their appearance or titles. For instance, we automatically respect a professor more than others, often perceiving them as taller just because they have a title. Similarly, in Milgram’s study, the authority figure’s lab coat and clipboard convinced participants to follow harmful orders. Con artists often take advantage of this by wearing uniforms or suits to appear credible.

While some authority figures, like judges or doctors, deserve our trust, it’s important to be cautious. To protect ourselves from those who misuse authority, we can ask two key questions:

1. Is this person genuinely an authority, or are they pretending? Are their credentials valid for the situation? For example, Robert Young played a doctor on TV and was used in coffee ads because people thought he was a real doctor.

2. Can we trust this authority figure to be honest? Do they have our best interests in mind? A waiter might recommend an expensive wine because they benefit from it.

Understanding these tactics can help us think more critically and make better choices.

“Often we don’t realize that our attitude toward something has been influenced by the number of times we have been exposed to it in the past.”

Major Takeaway

In "Influence: The Psychology of Persuasion," Robert Cialdini explores the six key principles that drive human behavior: reciprocation, commitment, social proof, authority, liking, and scarcity. Through engaging examples and experiments, Cialdini reveals how these principles shape our decisions and can be exploited by marketers and manipulators. The book emphasizes the importance of recognizing these influences to protect ourselves from unwanted persuasion. Ultimately, it serves as a guide to understanding the psychology behind compliance and decision-making, equipping readers with the knowledge to navigate social interactions more effectively and make informed choices in their personal and professional lives.

Video Insight from the Author, Robert Cialdini