The Laws of Influence: The Psychology of Getting to YES

The one book every person should read, and one that has helped me more than any other business publication, is “Influence: The Power of Persuasion” by Dr. Robert B. Cialdini. This book provides you with tools to craft compelling marketing messaging, obtain sales, and win arguments.


Bill Arnold

11/13/202312 min read

If you are like me, you have read hundreds of books about marketing and sales. I have a collection that would rival the Library of Congress. Many of those books I read have been responsible for honing my philosophy on business or giving me insights into marketing and sales strategies. It is safe to say these books have been impactful and helped me become a better marketing and sales professional.

I was recently asked, “If you could ONLY recommend one book, which one would that be?” You might think, with all the great business books I have read, that answer would take me a while to answer. It took me less than two seconds to respond. It is a book I have recommended to EVERY client and have required EVERY employee to read.

What is the book that transcends every vertical and is meaningful to every person regardless of their profession?

The one book every person should read, and that has helped me more than any other business publication, is “Influence: The Power of Persuasion” by Dr. Robert B. Cialdini. This book provides you with tools to craft compelling marketing messaging, obtain sales, and win arguments.

I first read this book when it was published in 1984 when the internet was a mere concept. I provide this context because, while it was originally written for the pre-internet era, it applies to the digital marketing era even more.

Dr. Robert Cialdini is the Godfather of Marketing Psychology. He has done over 35 years of rigorous, evidence-based research on what moves people to change behavior. His findings are found in over 20 books on psychological persuasion, but his original publication, Influence: The Psychology of Persuasion, is the foundation of them all.

Dr. Cialdini wrote this book after a comprehensive three-year study about why people say “yes” when asked to purchase something they didn’t need, or agree to do something when they preferred not to. Dr. Cialdini was personally plagued with this problem and wanted to figure out why he was compelled to say yes when he would rather have said no.

His book was recently updated, and he has identified seven Laws of Influence. These laws of persuasion are universal and apply regardless of your gender, age, nationality, religion, or political beliefs.

The Seven Laws of Influence

  • Law of Reciprocity

  • Law of Commitment & Consistency

  • Law of Social Proof

  • Law of Authority

  • Law of Liking

  • Law of Scarcity

  • Law of Unity

Each of these laws has a sound scientific basis as to why they work. Let’s examine them in detail.

The Law of Reciprocity: You have heard of the expression, "There is no such thing as a free lunch." That is the Law of Reciprocity. We are compelled to return favors and treat others as they have treated us. This is because we’re uncomfortable with feeling indebted to them. Don’t believe it? If a friend gives you a gift for your birthday, don’t you feel compelled to reciprocate theirs?

What makes the Law of Reciprocity so powerful is the obligation to do something in return is not always proportional in nature. A person who buys a $2 candy bar, from a colleague to help their child’s school fundraising efforts, will find the Law of Reciprocity works when they are later asked to buy a $25 raffle ticket.

TIP: The Law of Reciprocity works best when:

  • You are the first to give a gift

  • The gift is personal in nature

  • The gift is unexpected

  • Your return request is not immediate but close enough that they will remember

The Law of Commitment (and Consistency): Once a person commits to a course of action, they are more inclined to follow it through to a conclusion. Salesmen have known this for years and have capitalized on it by getting the buyer to agree to small, intermediate steps along the way to a purchase.

The key to this law is starting with small requests that have little or no commitment on the part of the person it is directed. Let that request play out, and progressively ask for a bigger commitment. Dr. Cialdini gives the example of a company wanting to erect a billboard in a neighborhood. The local residents were against it, but the objections were overcome by a series of small asks. First, the residents were asked to place a small placard in their window, then a lawn sign, and finally the billboard. There was a 400% greater acceptance when these steps were taken. The residents felt obligated to proceed in a manner that was consistent with their past actions and behavior.

TIPS: The Law of Commitment and Consistency works best when:

  • The follow-up request is close in time to the original commitment. A person is never more sure about the correctness of a decision than they are immediately after it was made.

  • The original commitment cannot have been coerced. It must have been an active choice made voluntarily.

  • The commitments have to feel real and binding on the individual. This law works best when the original commitment is done publicly and in writing.

The Law of Social Proof: We live in a society, where we are overwhelmed with information and do not have time to research every buying decision. That is why referrals work so well. We trust our friends, and if they recommend a restaurant, a movie, or a product, we are more likely to buy. This principle relies on people’s sense of “safety in numbers.”

With the advent of the internet, the world has sped up. We are on a 24-hour continuous news cycle, and we are constantly bombarded with products and services to purchase. Nobody has the time or energy to learn about everything they need to know about a topic, so we have developed shortcuts. One of these is the Law of Social Proof, which states we determine what is correct or good by what other people think is correct or good.

What is the internet if not a collection of people and organizations telling us what they think about everything? What do you do when you are in a new town and want to figure out what restaurant you should go to for dinner?

Many people check with services such as Yelp, which is essentially a collection of people telling us what is good and what you should avoid.

Most likely, there is not a single review from a person you know, but you trust and rely upon the opinions of people you will never know or meet. The collective opinions of absolute strangers influence your decision. We make fewer mistakes if we act by social evidence than if we don’t.

TIPS: The Law of Social Proof works best when:

  • The referral comes from a person or site that is perceived to be impartial.

  • For B2C, referrals from sites such as Yelp or Google work well.

  • For B2B, referral sites like G2Crowd, Software Advice, Capterra, etc. provide that social proof.

The Law of Liking: People are more likely to be influenced by someone they like and can relate to. This is why so many salespeople compliment us on matters totally unrelated to what they are selling. We like people who compliment us.

It should be no surprise that we are more influenced by people we like, for example, friends and family. However, the Law of Liking can also extend to complete strangers. People tend to like and be influenced by complete strangers if they see a connection between themselves and that stranger. Here are some examples:

  • Physical Attractiveness – It is no surprise that good-looking people have an advantage in the world. It is instinctive, that we automatically assign favorable traits to people we deem good-looking. This includes characteristics that have no relation to looks at all, such as honesty, trustworthiness, and intelligence. Is it any wonder, that we are also influenced by what this person says or does?

  • Similarity - In a massive study of 421 million potential romantic matches from an online dating site, the factor that best predicted a favorable match was similarity. (Influence) When you see someone who you feel has similarities, you tend to trust their advice more. You will notice that many television networks and social platforms are comprised of people with the same political beliefs. Everything that is communicated on those platforms rings true to them, because the person speaking has a similar belief system.

TIPS: The Law of Liking works best when:

  • Before you commence the sales process or a negotiation, spend time to build a rapport.

  • Exchange personal information, and find areas of commonality.

  • Look for ways to provide a genuine complement to them.

The Law of Authority: We are programmed to respect and listen to people who have a position of authority. This is why advertisers of pharmaceutical products employ doctors to front their campaigns. That is why advertisers use uniformed police officers to sell auto insurance. We have learned from an early age to respect and mind those in positions of authority.

There are two reasons this principle works so well. 1) We are taught from a very young age that obedience to authority is good, and disobedience is wrong. 2) In many cases, authority figures are experts who have taken the time and energy to develop specialized knowledge. Examples of pre-internet experts were doctors, lawyers, and academia. In today’s world, Subject Matter Influencers are also afforded that status. We listen and react to their advice and wisdom, because they have specialized knowledge that we have not taken the time to develop or the confidence to act on our own.

In the pre-internet world, we would identify people of authority by their titles (e.g., doctor, lawyer, etc.), and/or the clothes they wore (e.g., policeman, military, etc.). Today, we confer the mantle of authority based on three factors:

  • Expertise – Does the individual exhibit heightened knowledge about a topic that is not generally known without research or study?

  • Trustworthiness – Does the information ring true or can it be relied upon? Do they attempt to depict reality accurately, rather than serving their own self-interests? Any person who continually gives false advice will eventually lose their status as an authority.

  • Reach – To be an authority figure, you have to have followers who see you as relevant. The larger the group, the more people see you as an authority and someone who should be listened to and followed.

TIPS: The Law of Authority works best when:

The Law of Scarcity: The Law of Scarcity is based on the fundamental principle that people naturally desire things that are less readily available. When something is perceived as scarce, it triggers a fear of missing out, leading individuals to place a higher value on the item or opportunity in question. This psychological phenomenon has been observed across various domains, from economics to marketing and social psychology.

The law of scarcity works by triggering several cognitive biases and emotional responses in individuals. These include:

  • Showcasing Credentials: When attempting to influence others, it's crucial to establish your credibility upfront. Highlight your qualifications, achievements, and relevant experience to establish yourself as an authority in your field.

  • Utilizing Social Proof: People are more likely to follow the lead of others, especially when those individuals are considered authorities. Incorporate testimonials, endorsements, or case studies that demonstrate how respected figures endorse your ideas or products.

  • Establishing Expertise: Position yourself as an expert by consistently sharing valuable insights and knowledge in your area of expertise. Publish articles, give talks, or participate in relevant industry events to showcase your authority and build trust.

  • Referencing Credible Sources: When presenting information or making an argument, reference reputable sources and studies. This demonstrates that your ideas are backed by reliable evidence and increases your perceived authority.

  • Fear of Missing Out (FOMO): When faced with limited availability, people tend to experience a fear of missing out on something valuable. This fear drives them to take immediate action and make decisions they might not have otherwise made.

  • Perceived Value: Scarcity enhances the perceived value of an item or opportunity. When something is scarce, it automatically becomes more desirable and valuable in the eyes of the individual.

  • Competition: Limited availability often leads to increased competition among individuals. When something is scarce, people feel the need to compete with others to secure the limited resource, further driving up its perceived value.

  • Creating a Sense of Urgency: Highlight the limited availability of your product or service to create a sense of urgency. Use phrases like "limited time offer" or "while supplies last" to encourage immediate action.

  • Exclusive Offers: Provide exclusive offers or discounts to a select group of individuals. This creates a sense of exclusivity and scarcity, making the offer more enticing.

  • Highlighting Limited Stock: If you have limited stock of a particular item, make sure to emphasize this in your marketing materials. Let your customers know that the item is selling fast and may soon be unavailable.

  • Time-Limited Promotions: Offer time-limited promotions to create a sense of urgency and scarcity. Encourage customers to take advantage of the offer before it expires.

  • Using Social Proof: Highlight the popularity and demand for your product or service. When people see that others are interested in and purchasing your offering, they are more likely to perceive it as scarce and valuable.

The Law of Unity: The world has increasingly developed a tribal mentality, dividing everyone into two groups, “us” and everyone else. This is very similar to the Law of Liking, in that people are inclined to be influenced by, and say yes to, someone they consider to be “one of them.” Unlike the Law of Liking, this is based almost exclusively on who you see as part of your tribe, which usually is a group of people of a similar race, ethnicity, nationality, family, political party, or religion.

In the past few years, we have seen that the Law of Unity is arguably the most powerful law of influence. We live in a society with two belief systems. Half the population believes that COVID-19 vaccines saved lives, and the other half believes it was a conspiracy by the pharmaceutical companies to line their pockets. Half the US population believes that the 2020 Presidential election was stolen, and the rest believe that group lost touch with reality. This is all because we have aligned ourselves in tribes. While many companies have tried to remain apolitical, those who have not had often seen the power of tribalism. An example is the cancellation of Bud Light who violated the tribal norms by suggesting the LGBTQ community might enjoy their product.

  • Finding Common Ground: One of the key principles of the Law of Unity is finding commonalities with the person or group you're seeking to influence. Look for shared interests, experiences, or values that create a sense of unity. By highlighting these similarities, you can establish a connection and build rapport.

  • Using Inclusive Language: When communicating your message, use inclusive language that emphasizes togetherness and unity. Avoid language that creates divisions or emphasizes differences. By framing your message in a way that promotes unity, you'll be more likely to resonate with your audience.

  • Highlighting Shared Goals: Focus on the shared goals and objectives that you and your audience have in common. Emphasize how your proposal or idea aligns with their interests and aspirations. By demonstrating that you're working towards a common goal, you'll increase the likelihood of gaining their support.

  • Showing Social Proof: People are more likely to be influenced by others who are similar to themselves. Utilize social proof by showcasing testimonials, case studies, or success stories from individuals or groups who are similar to your target audience. This will create a sense of unity and reinforce the idea that others like them have already benefited from your proposal.

  • Building Relationships: Invest time and effort in building genuine relationships with your audience. Engage in active listening, show empathy, and demonstrate that you genuinely care about their concerns and needs. By building strong relationships, you'll strengthen the sense of unity and trust, making it easier to persuade and influence.

TIPS: The Law of Scarcity works best when:

The Power of “Because”: While Dr. Cialdini did not cite the Power of “Because” as one of the universal laws of persuasion, he did discuss the power of using this word to influence people to do as you asked.

The power of 'because' lies in its ability to provide a reason for your request. When you give a reason, even if it seems obvious, it triggers a cognitive response in the other person's mind. They feel compelled to comply, because they don't want to appear rude or unreasonable.

Dr. Cialdini conducted an experiment where participants were asked to request cutting in line to use a photocopier. The participants used three different approaches:

1. No 'Because': Participants simply asked, 'Excuse me, may I use the photocopier?'

2. Weak 'Because': Participants asked, 'Excuse me, may I use the photocopier, because I need to make some copies?'

3. Strong 'Because': Participants asked, 'Excuse me, may I use the photocopier, because I'm in a rush?'

The results were fascinating. When no 'because' was used, only 60% of participants complied with the request. However, when the word 'because' was added, compliance significantly increased. Even the weak 'because' condition, where the reason was obvious, led to a compliance rate of 93%. The strong 'because' condition increased compliance to a staggering 94%.

TIPS: The Power of “Because” works best when:

  • Being specific: When using 'because,' provide a specific reason for your request. This adds credibility and increases the likelihood of compliance.

  • Highlighting the benefit: Emphasize the benefit the other person will receive by fulfilling your request. This creates a win-win situation and strengthens your persuasive argument.

  • Using it in writing: 'Because' is not limited to verbal communication. Incorporate it into your written requests, such as emails or letters, to enhance their persuasiveness.

  • Practicing empathy: Put yourself in the other person's shoes and consider their perspective. Tailor your request using 'because' to address their needs and concerns.

  • Avoiding manipulation: While 'because' can be a powerful tool, it should be used ethically. Do not manipulate or deceive others with false reasons or exaggerated claims.


There are certainly a lot of great books on marketing or sales, but Influence: The Power of Persuasion” by Dr. Robert B. Cialdini has been the most beneficial to me and our clients. The laws of influence hold immense persuasive power. Every aspect of the content and every offer we create is reviewed to make sure it has incorporated one or more of the Laws of Influence.

TIPS: The Law of Unity works best when: