Since 2020

The 7 Principles of Influence

At the very top of the list of key models every marketer should know is the model known as the “Six Principles of Influence” or the “Principles of Persuasion.”

In more recent times, the framework has been referred to as the “Seven Principles of Influence” owing to the fact that a 7th principle called “Unity” was added some 30 years after its author first published the book which launched the original six principles into mainstream business awareness.

The book that started it all is called “Influence: The Psychology of Persuasion,” first published in 1984, which went on to sell millions of copies and establish itself as the bible of the sales and marketing industry.

Its author is Dr. Robert Cialdini — a behavioural scientist and educator, described as “the world’s most quoted expert on influence,” who has written “Pre-suasion” and is co-author of “Yes!: 50 Scientifically Proven Ways to Be Persuasive.” He is also Regents’ Professor Emeritus of Psychology and Marketing at Arizona State University and CEO of “Influence at Work,” a corporate training company focusing on ethical influence which consults to top firms such as Google, Microsoft, and Cisco.

Central to Cialdini’s body of work is the idea that humans use cognitive shortcuts.

Based on his research, there are a handful of timeless general psychological principles that people across all ages and cultures tend to rely on to make decisions and decide what products and people to trust.

We rely on these principles because we live in a complex information world in which we are bombarded by numerous purchasing decisions every day of the week. None of us have the time to perform a thorough background check of every single product we encounter and most of us don’t possess the technical expertise to accurately assess the validity of each marketing claim. 

Instead, we depend on convenient decision-making principles or rules.

Whether scrolling through products online or wandering the isles of our local supermarket, people widely use these quick rules of thumb in an unthinking manner as basic decision shortcuts for just about every kind of purchasing situation, whether we are buying an intangible idea or a tangible product.

In simple terms, these principles allow us to “buy quickly without thinking too much about it.”

For centuries, savvy sellers have been using these basic principles to their advantage to build trust, persuade, and ultimately gain people’s commitment. 

Sales and marketing professionals who are aware of the nature of each of these principles can produce a kind of “automatic, mindless compliance from people.”

With a more detailed outline of each principle to follow, the seven principles very briefly are:

  1. Reciprocity: people want to return favours
  2. Commitment and consistency: people want to remain consistent with past actions and commitments they have made
  3. Social proof/consensus: people are strongly influenced by what others think
  4. Authority: people tend to trust and obey authority figures (genuine and apparent)
  5. Liking: the more you like and can relate to someone, the more they will influence you
  6. Scarcity: the rarer something is, the more desirable and valuable it is
  7. Unity: we favour people from our in-groups who are “one of us”

These principles emerged from Cialdini’s study of salespeople or what he terms “compliance professionals” — essentially anyone whose goal is to gain your compliance in making a sale, signing a petition, agreeing to a deal, or saying “yes” to a simple request.

Unlike many marketing texts based purely on personal opinion, as a social psychologist, Cialdini initiated a major long-term scientific study of sales methods. The final framework was the result of about three years of experimental laboratory studies combined with undercover work immersed in the world of selling. Cialdini attended training sessions and shadowed salespeople in real-life customer situations as a trainee across industries as diverse as automotive sales, charity fund-raising, TV advertising, PR, recruitment, and telemarketing.

In case you might be wondering why there are only a small handful of principles when sales books often contain endless lists of techniques, Cialdini writes:

“Although there are thousands of different tactics that compliance practitioners employ to produce ‘yes,’ the majority fall within six basic categories. Each of these categories is governed by a fundamental psychological principle that directs human behaviour and, in so doing, gives the tactics their power.”

It should be kept in mind that the principles are a description of the persuasive tools that tend to work best, not a prescriptive outline of what tools the author thinks people should use. As such, the tools are like any powerful technology and can be used for good ends as well as unethical ones. Tricksters and con artists can leverage these principles of power for selfish motives, just as noble-minded individuals and organisations can use them to advance the common good.

A major driving force behind his work was the desire to identify and neutralise the undue influence of certain sales techniques. 

Self-described as an “easy mark for the pitches of peddlers, fund-raisers, and operators of one sort or another,” Cialdini was deeply fascinated by the various strategies and tactics that salespeople used to get people like himself to hand over their trust (and their money).

Rather ironically, a book which was fundamentally about how to guard against sales tactics went on to become the best-selling text of the sales and marketing industry, giving millions of professional marketers insight into the hidden levers of psychological power.

Ultimately, the principles of influence have two broad applications: 

  • (1) as a “how-to” guide to improve the odds of being successful in one’s persuasive attempts.
  • (2) as a defense against the “dark arts” of sales, for people like Cialdini who often struggle to say “no” and want to know if they’re being unduly influenced by a hidden sales tactic. 

The principles are considered to be universal. Certain principles work better under certain conditions than others, but generally speaking they will apply in most types of buyer-seller scenarios, across all major demographic categories including age, race, gender, and culture. 

To preserve the essence of the framework as intended by its author, the descriptions below keep relatively close to Cialdini’s descriptions across written material, talks, and lectures. This summary includes a mix of original examples as well as more recent updates. 

Let’s examine each of the original six principles in turn — plus the 7th principle of Unity that Cialdini has added to the framework in recent years.   

Principle #1: Reciprocity

“The rule says that we should try to repay, in kind, what another person has provided us.”
— Robert Cialdini

Reciprocation refers to the social practice of like-for-like exchange, mutual sharing, or giving and receiving. 

When given something, people will tend to feel a very strong sense of obligation to settle the debt or return a favour done to us.

We generally want to help others who have helped us. It’s natural to feel positive feelings for people who have done us right, just as we remember people who have done us wrong. Humans will generally experience a strong automatic emotional urge to repay one action with a similar one in response (whether positive or negative). 

The principle or rule of reciprocity recognises that small favours, acts of kindness, gifts, invitations, helpful gestures, and making an effort on another’s behalf can strongly motivate the desire to give something back in return. 

In other words, salespeople can greatly enhance the chances of gaining commitment from others by first doing them a little favour.

A series of studies done on restaurants showed that a server who gave diners a complimentary gift with the bill such as a small mint would typically increase tips by 3%. If two mints were given, the tips would increase to 14% — a quadrupling in size. But if the server gave one mint, went to leave, stopped, turned back, and said “For you nice people, here’s an extra mint” the tip size again increases — to 23%.

Whether someone buys you a drink, gives you a compliment, speaks up on your behalf, gives you a business referral, or sends you a birthday card, you’ll probably feel a sense of obligation to return the good deed at some point. Even if you don’t return the favor immediately, it’s likely to be remembered and to generate positive sentiment that can be the basis of further developing a relationship. 

In the case of a salesperson who sends you a handwritten greeting card in the mail, you might not necessarily send back another card in return straight away, but you might be motivated to drop by their office for a visit or pick up the phone and give them a “thank you” call. Joe Girard, the man named by the Guiness Book of World Records as the “world’s greatest salesman” for selling Chevrolets, would send 13,000 former customers a holiday greeting card with a printed message each month.

Interestingly, the sense of obligation is such a strong social force that many of us are automatically conditioned to respond warmly in cases where we don’t particularly like the person very much. However, generally speaking, people are more likely to repay small, unconditional favours. If the gift is too big or there are clearly strings attached, it’s less likely to generate the reciprocal bond.

Perhaps the most ingenious application of the reciprocity principle comes from the Hare Krishna Society. During the 70s, members of this spiritual sect were known to hang out in airports and give out flowers to passengers coming and going. If a stranger tried to give the flower back, the Krishna member would say something like, “No, it is our gift to you.” When the stranger insisted on giving back something in return, only then would the Krishna member talk about making a contribution to the society. 

This tactic produced large-scale financial gains for the group in over 300 centres in and outside of the U.S.

Principle #2: Commitment and consistency

“It is, quite simply, our desire to be (and to appear) consistent with what we have already done.”
— Robert Cialdini

The principle of consistency refers to the powerful human desire to remain consistent with our past actions and commitments, especially in public.

There are two sides to this principle. 

Firstly, it involves our internal need to remain true to ourselves and to our self-image, even when nobody is around to hold us accountable, since we believe we are (or are not) “that sort of person.” 

Secondly, it is driven by an external social pressure we encounter (especially in large public groups) to not appear foolish in the eyes of others by appearing contradictory, hypocritical, erratic, two-faced, or confused.

Once we have taken a stand in public or find ourselves voicing an opinion in front of someone, we will encounter both social and internal pressure to remain true to our word. This feeling can become even stronger when later presented with conflicting evidence or more rational options, leading to the phenomenon of “doubling down.” 

If we have previously donated money to a charitable cause, the telemarketer may gently remind us of our good deeds and our desire to continue to be a good person. If we ourselves have already paid for the cost of the regular car service, why not throw in a few extra service upgrades? 

Once we have committed ourselves to a cause or conclusion, we will search for logic to justify our decision. The more effort that has gone into a position, the more susceptible someone becomes to influencing tactics that recgonise this need to remain consistent.

This principle often takes the form of the “foot in the door” approach, also known as the “escalating commitments” sales tactic. 

The principle is in action anytime a seller offers a low-commitment, small sale intended to pave the way for larger, more frequent purchases. By gaining even a very small level of commitment in one direction — a small acknowledgement, a harmless concession, a reasonable first question (followed by another, and then another) — the stage is set for gaining a bigger agreement shortly after.

This tactic was employed to stunning success by Chinese communists by getting American prisoners of war (POWs) to agree to small statements at first such as “America isn’t perfect.” Once the POW had complied with these minor requests, the Chinese were able to use these statements to their advantage and turned many prisoners into collaborators.

Another powerful example of gaining commitment to a brand is by running contests whereby customers have to write in 100 words or less why they like using a particular product. The winner of the contest gets a prize for the most creative or compelling short answer. Rather than trying to force agreement, the entry participants start to think hard about why they like the brand or product and begin to gush with praise in their own words.

Principle #3: Social proof

“This principle states that we determine what is correct by finding out what other people think is correct.” 
— Robert Cialdini

Arguably the most powerful of the seven principles, humans are powerfully influenced by the opinions and behaviours of others, particularly those in the same peer group.

We can easily come under the spell of fashions, trends, groupthink, and peer pressure, even in the most apparently well educated and rational organisations.

Monkey see, monkey do.

According to Cialdini, “the principle applies especially to the way we decide what constitutes correct behaviour. We view a behaviour as correct in a given situation to the degree that we see others performing it.”

From a marketing perspective, if we want to stimulate a request for compliance, then an extremely effective tool is evidence or proof of what other people think (social proof).

Many advertisements make use of phrases such as: 

  • “The number #1 selling” 
  • “Fastest growing” 
  • “Most popular” 
  • “Crowd favourite” 
  • “Trending” 
  • “Most clicked” 
  • “Millions of customers can’t be wrong”  

Customer testimonials are perhaps the most prevalent and obvious example of this, but the marketing world is full of novel applications of the rule (although they should not necessarily be copied). Some of the more notorious examples include:

  • TV executives are known for using canned laughter or laugh tracks on their sitcoms because it has been shown to make audiences laugh longer and harder. 
  • It’s not uncommon for nightclub owners to manufacturer long wait lines despite having plenty of room inside. 
  • Evangelical preachers have been known to seed their audience with ringers to respond positively, give testimony, and generate greater enthusiasm from the audience. 
  • Waiters and waitresses may add a small number of coins or notes to tip jars to stimulate further contributions (and remove the fear of going first).

The rule of social proof applies especially under two conditions. 

The first is uncertainty. When we don’t know what to do, find ourselves in an unfamiliar environment, or don’t feel confident about our own abilities, we naturally turn to others. 

The second condition is observing the behaviour of people similar to us. For example, we are more likely to find a weight loss testimonial compelling if the person giving the testimonial is of a similar age, gender, social status, or shares the same personal struggles that we do.

Herd mentality is a double-edged sword. It can lead to acts of heart-warming group solidarity just as it can lead to the infamous Jonestown cult massacre.

The difficulty is that, most of the time, social proof provides valuable information. “With it, we can cruise confidently through countless decisions without having to investigate the detailed pros and cons of each.” 

It is often reliable in many contexts to follow the crowd, but the convenience of the rule is simultaneously its major strength as well as its major weakness. Thus, we find ourselves with a classic problem: how to use a tool that both benefits and imperils our welfare.

One of the most interesting examples of how to leverage this principle in our lives is by recognising the importance of the first follower. 

People are naturally resistant to standing out in a crowd and looking different. Most of us don’t want to take the first step. Whether we are influencing teams or customers, providing evidence of someone who has taken the first step (the first follower) is a great way to overcome initial resistance. 

With one follower comes another. Before long, you have a small group. And all large movements have their beginnings in small groups.

Principle #4: Liking

“As a rule, we most prefer to say ‘yes’ to the requests of people we know and like.” 
— Robert Cialdini

“Liking” refers to just that — liking a person. 

It’s the degree of affection, appreciation, admiration, or positive feeling we have towards another person.

Liking has more to do with trusting a person’s character because we like something about them as a person, in comparison to trusting someone because they are knowledgeable, competent, or appear to have an air-tight argument, though it should be said that practically any major or minor detail about a person can influence how much we like them.

Beyond liking someone for something about their personality, it’s also the case that liking is influenced by how well we know someone and for how long we’ve known them for. We are far more likely to purchase a product by referral through a friend or someone we already know, if not trust. Simple familiarity influences liking, and liking influences purchasing.

Possibly the most spectacular example of this principle in action from a marketing perspective is the “Tupperware party.” The homeowner (who would receive a percentage of the sales) would invite neighbours into the comfort of their home to listen to a Tupperware representative present their air-tight sealed containers. Rather than relying on the retail sales concept, the Tupperware Corporation recognised the power of a request coming from someone people already know and like to the tune of hundreds of millions of dollars. In fact, requests of this kind that rely on the strength of a known social bond are twice as likely to result in a product purchase than if the product is being considered by itself.

Another related sales technique is the “endless chain” method of asking a customer for the names of friends or people they know who they think would also benefit from the product. The salesperson could then call the third party with a foot in the door via the friend “who suggested I call on you.” Not only does this call tactic establish some kind of familiar link, but to turn down the salesperson therefore becomes extremely difficult because it becomes like turning away one’s friend.

People have a hard time separating the request from the requester, or the merits of the deal from the person who is presenting it. If we like the source, we tend to overestimate the worth of the deal. If we have a negative feeling about the source, we are more likely to underestimate the worth of the deal.

The tendency to overestimate someone’s abilities or the merits of their case based on unrelated personal qualities such as their smile or good looks is known as the Halo Effect. 

This is one of the reasons why trial attorneys take tremendous care in making sure the jurors like their client. It’s also why people are taught to pay close attention to how they look and sound when attending a job interview. Appearance and first impressions count. People can make up their minds about someone they’ve only just met within a few seconds of observation based on small things that may have nothing to do with the logical merits of the issue at hand.

“Likeability” however can be a very broad and subjective thing. After all, one of the reasons why there are so many different products in the market is because people don’t all share the same tastes and don’t like the same things. How are we to know what factors will cause one person to like us, and another to dislike us? It’s a question social scientists have been asking for decades. 

One thing research consistently indicates is that people are more likely to buy from good-looking people, vote for good-looking politicians, and hire good-looking candidates. We often use appearance, looks, and confidence as a measure of competence.

Obviously, this can seem a bit unfair. If we are not especially good-looking, charismatic, or likable, we may be at a disadvantage in sales. Some people are just more likeable than others.

What’s a seller to do?

One of the most obvious ways salespeople tend to influence likability is through the use of compliments. We will often like people who appear to like us first. Praise, recognition, and positive remarks are how we show people we like them. Flattery can go a long way, assuming the flattery is genuine and perceived to be genuine.

Another solution to the problem of likability lies in similarity: we like people who are similar to us.

In general, the more we can identify similarities or similar traits (rather than be made aware of differences) the more we are likely to soften our stance towards a stranger. 

We tend to like people who are similar to us in some way; for instance, if we know they have the same hobby or grew up in the same suburb. 

Finding common ground is one of the most effective ways to influence likeability. 

Brands will often leverage this rule through the principle of association: by the linking of products to celebrities and well-liked individuals in pop culture who the audience already has a strong emotional connection with. The familiarity we have with the famous person can be expected to “rub off” on the product and instantly make consumers more comfortable with something that would otherwise take a much longer time to be liked under normal conditions.

Principle #5: Authority

“We are often as vulnerable to the symbols of authority as to the substance.”
— Robert Cialdini

As children, we learn to follow the rules — of parents, teachers, doctors, priests, leaders, governments, and revered institutions. 

We often defer to the judgment of the experts and the people in charge, partly because there are punishments if we disobey and partly because we tend to assume that more senior people know more than we do. If someone has a Ph.D. or is a professor at a prestigious university, who are we to argue with this esteemed expert?

In many cultures, there is a strongly established custom of respecting one’s elders as well as people who are placed in more senior positions. For example, in the airline industry, Captainitis refers to a flight crew’s reluctance to question a senior pilot’s decisions, which has been documented to have disastrous consequences.

While there are obviously varying degrees of difference across cultures in how much respect is afforded to a particular political leader, health care authority, or a local elder, most people tend to retain the basic tendency from childhood to believe what certain authorities have to say without too much resistance. Because of this widespread tendency to automatically and uncritically comply with the word of authority, one of the strongest ways to influence people is by demonstrating relevant credibility, qualifications, and expertise on a subject.

Positioning oneself as an “expert” becomes a central modern marketing challenge and is why we often see long lists of acronyms at the bottom of people’s email signatures.

Where the principle of “social proof” recognises that people are easily influenced by evidence of the behaviour and opinions of other people, the principle of authority recognises that people are generally more susceptible to influence by someone who is able to demonstrate “subject proof.”

In an ideal world, people would only trust genuine “experts” and we would have extremely reliable ways of demonstrating genuine expertise to avoid being taken advantage of by false authorities. In reality, people often respond to symbols of authority in lieu of its substance.

The most common form the principle of authority takes is the use (and sometimes) misuse of job titles and, particularly in recent times, the co-opting of the name of science to lend credibility to an issue. “According to science” and “studies show” are perhaps two of the most overused examples that rely on an appeal to scientific authority, when the scientific opinion may only be small and not representative of the larger scientific community.

Medicine is a particularly noteworthy example of tending to believe in the word of someone simply because they are a “doctor.” In one study on nursing compliance, a researcher who was not a doctor made the same phone call to 22 separate nursing stations and gave the nurse an illegal and dangerous directive to administer a 20-milligram drug to a specific patient. In 95% of cases, the nurses complied with the request (and had to be stopped by the researchers before delivering the drug), simply because the man on the phone identified himself as a doctor. 

Apart from impressive titles, clothing is another kind of authority symbol that can influence us. Certain fashion styles and expensive clothes, jewelry, cars, and other status symbols may be given special attention and significance. Social research shows giving a passersby on the street a series of random requests such as picking trash or standing on the other side of a bus-stop sign is much more likely when the requests come from an individual wearing a security guard’s uniform (92% compliance) than being dressed in ordinary street clothes (42% compliance).

One of the most interesting and frightening examples of obedience to authority which Cialdini gives particular attention to comes from Stanley Milgram’s famous experiment in which people were instructed by an authority figure to give shocks to a stranger at escalating levels of danger. The participants didn’t know the person they were giving an electrocution to was actually an actor in the experiment. However, the majority of participants went to deadly shock levels, despite the screams of the stranger, simply because a person in a lab coat told them to continue with the experiment.

This doesn’t mean marketers should put on fake uniforms and create a bunch of fancy sounding terms to give an air of respectability. But it does mean that we should be aware of the fact that authority symbols, clothing, and titles often have the power to short-circuit our more rational powers of judgment.

Principle #6: Scarcity

“As a rule, if an item is rare or becoming rare, it is more valuable.”
— Robert Cialdini

The principle of scarcity recognises that people pay particular attention to opportunities and products which are (or seem to be) exceptionally unique, rare, or less available.

This principle is most likely to hold true under two special conditions. First, scarce items are heightened in value when they have only recently become rare. Second, scarce resources attract our interest when we must compete with others to obtain them.

We often see this principle in action through common marketing phrases such as “limited time” deals, “exclusive” offers, “limited spaces available,” or “one-time only” specials. 

It’s also seen in what is arguably the most basic marketing principle of all: competitive advantage. A brand’s unique selling proposition (USP) is about explaining to the market how you are different from all the other brands and what you can supply that no one else has to offer, whether it be a cheaper price or a patented formula.

One of the key triggers of scarcity applies when opportunities are restricted to us. For example, the censorship of a book may suddenly cause a surge of interest in the material. We often find a piece of information more persuasive if we think that we can’t get it elsewhere.

Being told that we’re not able to purchase a particular product can suddenly raise our desire to have the item, despite nothing having changed materially in terms of the item’s practical value. Toy stores are known to carry a limited supply of certain toys in order to generate more demand, knowing that “out of stock” signs are often taken by parents (and investors) as a strong indication of value.

“Final chance” phrases can activate our fear of missing out (FOMO). In psychology, there is a well known cognitive bias known as Loss Aversion, whereby the pain of loss or missing out on something is psychologically more powerful than the pleasure of gaining something of equal value.

Besides tapping into our fear of loss, the principle also reveals that we are strongly influenced by the sense that an item is special or unique — and therefore we should want to take part in an exclusive club or bid for that very rare item.  

There are various reasons why something might be considered rare, special, unique, world-class, or unlike anything else. A basic necessity like water is generally abundant in developed countries. But in a water shortage, the resource becomes limited just as need skyrockets, changing the value of what was a cheap and widely available commodity into a rare (and therefore potentially very expensive) luxury good.

As the economic law of supply and demand tells us, the greater the demand for something, the more competition there is to obtain the item of value, and sellers can charge a higher price accordingly — because the market will pay handsomely for it. 

Collectors of trading cards and eBay sellers are highly attuned to “limited edition” prints and “special collectors” items, which can be cause enough to justify a seemingly absurd price tag.

It’s a rare person who isn’t influenced by the principle of scarcity.

Principle #7: Unity 

“The Unity rule of influence can thus be worded: People are inclined to say ‘yes’ to someone they consider one of them.”
— Robert Cialdini

In the new and expanded edition of “Influence,” Cialdini formally introduces a 7th principle of influence he calls “Unity.” This principle recognises that when someone is seen as part of our in-group, tribe, family, or team, we are significantly more likely to favour that person and allow their behaviour to influence our own, whether consciously or subconsciously.

In America, financial misconduct by an adviser is twice as likely to be copied by another if the two share ethnicity. In a large study in India, loan officers approved more loan applications and gave more favourable terms to applicants of the same religion. In a Hong Kong restaurant, customers were less willing to blame a server who shared their last name. In Ghana, customers were able to negotiate a lower fare with a taxi driver when they shared the same political party. In international soccer matches, players from a referee’s home country receive 10% more beneficial calls. In NBA games, researchers found that referees are significantly less likely to call fouls against players of the same race. And the list goes on.

Unity goes much deeper than the Liking principle, which deals more with similarity, commonality, and familiarity. The Unity principle is really about shared identity. According to Cialdini “it’s about our tribe-like categories that individuals use to define themselves and their groups, such as race, ethnicity, nationality, and family, as well as political and religious affiliations.” 

While we might get along with a colleague at work because we are of a similar age and enjoy the same kinds of TV shows and have common research interests, we won’t necessarily have a Unity relationship in the same sense that we have with someone who is a close family member, such as a sibling or spouse. In a Unity relationship, we are not just recognising that someone is “like us,” but that they are “one of us.”

In a Unity relationship, there is a blurring of “self” and “other.” The needs and welfare of others become entwined with our own interests. Among these other-selves, we are more likely to be open and honest, go out of our way to offer emotional support, be lenient in matters of punishment, and we’re also more likely to look to these people for moral guidance and to use their behavior as a compass for how to act.

The in-group favoritism to our own kind and kin appears to be primitive in origin, appearing in human infants as well as other primates. However, the fact that something is natural doesn’t necessarily mean that it is right. It should be noted that the principle of Unity, like the other six principles of influence, applies whether we think it’s fair or not. It’s an observation about how humans are influenced. Identity is an important aspect of our social reality, and recognising that it is the case helps us make better decisions. 

An interesting fact about Joe Girard who held the title of “Greatest Car Salesman” by the Guinness Book of World Records was that Girard was of Sicilian heritage and his name at birth was “Girardi.” He later changed his name because certain customers didn’t want to do business with a “Dago” (an ethnic slur for someone of Italian descent). It may not be fair that some customers don’t want to buy a car from someone with a particular name, but Girard recognised the principle of Unity had a powerful effect on people’s perceptions and, in an industry where split-second impressions count, he was able to turn a weakness into an advantage. 

By understanding the power of shared identity, a communicator is able to persuade more effectively. When genuine commonalities of identities can be recognised, the communicator will be more likely to hear “yes” to requests, proposals, and recommendations. The principle also serves as a guard against unethical or irrational persuasive conduct. The more aware we are of the fact that people (including ourselves) can be disproportionately influenced by the facts of identity, the better equipped we are to make more rational decisions by focusing on the merits of the case at hand and be less influenced by tribalistic concerns.


“All the weapons of influence discussed in this book work better under some conditions than under others.”
— Robert Cialdini

The core six principles are reciprocity, commitment and consistency, social proof, liking, authority, and scarcity. Cialdini later added a 7th principle called unity.

The principles of influence represent general decision making shortcuts that people often default to rather than giving a fully considered analysis of the situation. These principles are used as convenient rules of thumb to judge the substance of a message without having to put much effort into looking at the substance of the message itself. 

We are especially likely to fall back on these principles in situations where we experience cognitive overload, are feeling rushed or stressed, or find ourselves in unfamiliar situations and aren’t sure about how to proceed.

The rules are relevant to practically everyone, not just marketers and salespeople. We are all marketers in the broadest sense of the word. We want people to buy our ideas and we all make efforts to influence others. Understanding these principles at a deeper level will help improve our ability to persuade.

The principles help us understand why certain strategies work or are likely to improve the odds of success, and why other kinds of strategies are less primary. It helps us to direct our energy and attention on what delivers returns. The more time we spend learning the intricacies of each principle and associated strategies, the better we will be at tailoring our marketing message to “press the right buttons.”

The principles importantly also help us recognise when unethical behaviour may be present or that a salesperson is using them in an exploitative manner. Deeper knowledge of these principles helps us guard against being taken advantage of.

When we use the principles dishonestly with intent to deceive others and gain advantage over them, we are engaged in the process of manipulation.

When we use the principles ethically and honestly to benefit others we are engaged in the process of influence.