Synopsis and Summary: Unveiling Robert Cialdini’s Influence, including the 7th Element – Unity

In his 1984 book, “Influence: The Psychology of Persuasion,” Dr. Robert Cialdini presents six powerful principles that shape the way individuals are influenced by others.

Combining expert insights from psychology, marketing, and behavioural science, Cialdini offers readers a comprehensive understanding of the various tactics used to sway their decisions in everyday life.

In addition to the six well-known principles, there is an often overlooked yet vital seventh element Cialdini added 32 years after the original publication. He called it Unity, and included it in his follow up book: Pre-suasion (chapters 11 and 12).

The unity principle is similar in concept to Seth Godin‘s definition of culture in his book This Is Marketing, namely: “People like us, do things like this

Cialdini’s work emphasizes the importance of ethical influence and reveals how to recognize when these principles are being used in both beneficial and manipulative ways.

By grasping the underlying mechanisms of persuasion, readers are better equipped to resist unwanted attempts at coercion while promoting positive change.

With its timeless wisdom and actionable insights, “Influence: The Psychology of Persuasion” remains a must-read for anyone interested in better understanding the complex psychology that governs human decision-making.

Key Takeaways

  • Cialdini’s book explains six principles of persuasion.
  • The lesser-known seventh element, Unity, can be found in the follow up book: Pre-suasion.
  • Understanding these principles can help resist manipulation and promote ethical influence.
  • The book combines psychology, marketing, and behavioural science to explore human decision-making.

The Principle of Reciprocity

The Principle of Reciprocity is, perhaps, the key concept from Robert Cialdini’s influential book, Influence: The Psychology of Persuasion.

This principle is based on the human tendency to feel indebted when someone offers a gift or does a favour for us. The concept of reciprocation is deeply rooted in human society, and this innate sense of obligation compels people to return favours, even in response to small gifts or gestures.

One of the reasons the reciprocity principle is so powerful is that it generates a feeling of uninvited debts. When someone receives a gift or favour, they may not have asked for it, but they still feel obliged to return the favour in some way. This can be seen in a variety of social situations, ranging from a friend helping with a move to a neighbour offering assistance during a crisis.

In marketing and sales, the reciprocity principle is often harnessed through the use of small gifts or favours to create a sense of obligation in potential customers.

These small acts of kindness encourage the receiver to be more open to the persuader’s suggestions, and to make purchases or take other actions they might not have considered otherwise. Examples include free samples, complimentary services, or promotional items.

It’s important to remember that the principle of reciprocity should be used responsibly and ethically if a business values its long-term reputation. While it can be an effective tool in persuasion, it is crucial therefore, not to manipulate or exploit others for personal gain.

By understanding and respecting the power of this innate human tendency, individuals can harness its potential for positive influence in both their personal and professional lives.

The Principle of Commitment and Consistency

Another key idea discussed is the principle of commitment and consistency. This principle suggests that people have a strong desire to act consistently with their previous decisions, actions, and commitments. Like all other principles, commitment and consistency play a crucial role in guiding human behaviour, especially in decision-making.

When individuals make a commitment, particularly a public commitment, they tend to stand by their decision. This occurs because people want to maintain a self-image aligned with their commitments. By acting consistently with their previous commitments, individuals can preserve their positive self-image and avoid the discomfort of cognitive dissonance, which arises when their actions conflict with their beliefs.

The power of commitment and consistency can be observed in various settings, such as sales and marketing, where companies often use tactics to encourage customers to make small commitments. For example, offering free trials or asking customers to sign up for a special offer can lead to customers maintaining consistency in future decisions and eventually becoming loyal buyers.

Understanding the principle of commitment and consistency enables people to recognize and manage its effects. By being aware of how this principle influences behaviour, individuals can make more informed decisions and resist unwanted manipulation. In addition, understanding the role of public commitment and its influence on self-image can aid in effectively applying the principle in negotiation, persuasion, and conflict resolution.

So, the principle of commitment and consistency is an essential factor in human decision-making and behaviour. Its influence can be harnessed for both ethical purposes and manipulative tactics. By understanding its power and effects, people can make better choices and navigate various social interactions with greater ease.

The Principle of Social Proof

The principle of social proof is a powerful concept in understanding human behaviour. This psychological and social phenomenon demonstrates that people tend to copy the actions of others when deciding how to behave in uncertain situations.

Social proof plays a significant role in guiding people’s actions as they seek guidance from those around them. In essence, individuals consider the behaviour of others as evidence of the appropriate way to react. This principle is particularly prevalent when people face uncertainty, which often leads them to rely on external cues to make decisions.

One example of how social proof affects human behaviour can be found in advertising and marketing. Companies often use testimonials and customer reviews as a means to showcase their product’s popularity and increase its appeal. The underlying assumption is that if a large number of people use and approve a product, it must be worth trying. This creates a sense of trust and reliability in the consumers’ minds.

Social proof can also be observed in everyday situations, such as dining at a restaurant with a long queue. The perceived popularity of the restaurant implies high-quality food or a positive experience, encouraging others to join the queue and try it for themselves.

However, the social proof principle has its limitations. Blindly following the crowd may, at times, lead to unfavourable outcomes. For this reason, individuals should balance their reliance on social proof with critical thinking and personal judgment.

In conclusion, the principle of social proof plays a crucial role in shaping human behaviour, especially in situations involving uncertainty. It is essential to be aware of this principle’s strengths and limitations when making decisions based on the actions of others.

The Principle of Liking

The next principle is the principle of liking. This principle highlights the fact that people are more likely to be influenced by those whom they like. Three significant factors contribute to liking: similarity, relationships, and physical attractiveness.

First, similarity plays a crucial role in establishing and maintaining positive connections between people. Research indicates that we are naturally drawn to individuals with whom we share common interests, beliefs, and values. This sense of similarity fosters a bond of trust and camaraderie, making us more receptive to the opinions and suggestions of those we consider similar to ourselves.

Second, relationships also impact our ability to influence and be influenced by others. When strong relationships are established, the mutual affection and understanding create a more supportive environment for persuasion. Building rapport and maintaining open communication serve as foundations for strong relationships and increase the likelihood of successful persuasion efforts.

Physical attractiveness is the third factor that can influence our susceptibility to persuasion. While it might seem superficial, studies have shown that people often rate attractive individuals as more trustworthy, competent, and persuasive. Our predisposition toward attractive individuals can make their ideas and opinions more appealing and influential.

Cialdini’s principle of liking is a powerful tool in the art of persuasion. By understanding and leveraging the intricate dynamics of similarity, relationships, and physical attractiveness, individuals can increase their persuasive abilities and foster more positive connections with others.

The Principle of Authority

The principle of authority is a central concept in Robert Cialdini’s work on influence and persuasion. This principle states that people are more likely to follow recommendations or instructions from someone who is perceived as an authority in a particular field.

Authority can be conveyed through various means, including titles, symbols of authority, clothing, and other status symbols. People often attribute greater knowledge and credibility to someone with a high-ranking title, such as “professor” or “doctor.” This is because these titles indicate a level of expertise in their respective fields, leading to greater trust in their opinions and advice.

Symbols of authority can also play a significant role in persuading people. For example, a police officer’s badge or a judge’s gavel carries a sense of power and authority, making people more inclined to heed their requests or follow their rulings.

Similarly, clothing can be an effective means of showcasing authority. Uniforms, such as those worn by military personnel or medical professionals, signify their expertise and position in society. When individuals are dressed in this manner, people are more inclined to view them as knowledgeable and trustworthy.

Status symbols can further contribute to the perception of authority. Possessing items such as luxury cars, expensive watches, or living in an upscale neighbourhood can signify an individual’s success and thus conveys a sense of authority. People may be more likely to listen to someone who projects an image of success and authority through their material possessions.

Being mindful of the principle of authority can help readers become more discerning when faced with persuasive messages. By recognizing the various ways authority can be conveyed, it becomes easier to decipher whether someone’s advice or opinion should be trusted based on their actual expertise or merely their appearance.

Moreover, understanding this principle enables individuals to use it ethically when they need to persuade others, by demonstrating their credibility and knowledge in a particular field.

The Principle of Scarcity

The principle of scarcity is a key concept used in sales tactics. This principle is rooted in the idea that people tend to find scarce resources more attractive and valuable. This happens because scarcity tends to create a sense of urgency, with individuals fearing that they might miss out on an opportunity due to limited availability.

Scarcity works by influencing people’s perception of value. When an item is believed to be in short supply, its perceived value increases, subsequently generating more demand. The scarcity principle explains that opportunities appear more valuable when they are limited or harder to obtain.

This is a driving force behind many marketing strategies, often using phrases like “limited time offer” or “only a few items left in stock” to create a sense of urgency and encourage customers to make a purchase.

In situations where there is competition for limited resources, the scarcity principle plays an even more significant role. In the face of competition, individuals are likely to act more aggressively to secure the scarce resource, fearing that someone else might snatch it away.

This competitive nature can often be observed at auctions, where bidders can become more determined to win when faced with rival bids.

The principle of scarcity is not only applicable to tangible products but also to information, experiences, and even human relationships.

For example, exclusive access to information or events can generate strong interest and curiosity among people, making them feel privileged and more attracted to the opportunity. In the context of human relationships, individuals might find someone more interesting or attractive if their time, attention, or presence is known to be in short supply.

The Missing 7th Principle – Unity

In Robert Cialdini’s influential book, Influence: The Psychology of Persuasion, he initially presented six principles of persuasion. However, afterward, he identified a seventh principle, known as Unity. This new addition focuses on the power of shared identity and the way it can shape our decision-making processes.

Unity emphasizes the importance of fostering trust and building strong relationships with others. When we perceive someone as part of our group or sharing a similar identity, we are more likely to trust and be influenced by them. This concept is particularly relevant in today’s interconnected world, where people are increasingly seeking belonging, understanding, and connection with others.

One key aspect of unity is the idea of kinship, which is a natural bond we share with our family members. This bond can also extend to people who we view as part of our extended “family” or close community. By utilizing the unity principle, individuals can tap into these powerful connections and use them to enhance their persuasive abilities.

For example, a politician might appeal to unity by emphasizing their shared background and experiences with their constituents. This creates a sense of trust and understanding, allowing the politician to establish a deeper connection with their audience. In a similar vein, a marketer might leverage unity by highlighting a product or service’s alignment with the values and beliefs of their target audience.

The 7th principle of Unity (highlighted in Robert Cialdini’s book: Pre-suasion) showcases the potential of shared identity in persuasion. By recognizing and leveraging the power of trust, relationships, and unity, individuals can heighten their influence and achieve greater success in their personal and professional lives.

Applications of the Principles

A primary application of these principles is in sales and marketing. Salespeople often utilize these principles to persuade potential customers to make purchases or agree to requests. The principle of reciprocity, for example, encourages giving something to someone in the hopes that they will feel obliged to return the favour.

Sales professionals might use this technique by offering free samples or promotional gifts before asking customers to make a purchase. This can be seen commonly in supermarkets where free food samples of products the supermarket is promoting are often on display on the delicatessen counter.

Another principle, social proof, is frequently employed in advertising and marketing campaigns. This technique involves showcasing the popularity and acceptance of a product or service to sway potential customers. For example, businesses might share testimonials, social media likes, or statistics about the number of satisfied customers to persuade others to follow the crowd.

Cialdini’s principles also have applications in the realm of negotiation, where individuals and businesses employ various strategies to achieve their desired outcomes. The principle of liking advises that people are more likely to comply with requests from individuals they like or find attractive. Being friendly, genuine, and finding common ground can help negotiators build rapport, increasing the likelihood of successful outcomes.

The principle of authority, another of Cialdini’s key concepts, deals with the human tendency to obey authoritative figures. Companies or individuals seeking to establish a sense of credibility can harness this principle by highlighting their expertise, credentials, or experience.

While these principles have proven to be effective in achieving persuasive outcomes, it is essential to be cautious of manipulation, which can arise in the process. Many individuals may use these principles to exploit mental shortcuts, taking advantage of others’ cognitive biases to push a personal agenda rather than fostering a mutually beneficial relationship.

The seventh element, unity, plays an essential role in fostering a shared sense of identity, which further enhances the persuasiveness of the other principles. By emphasizing shared values, beliefs, or backgrounds, communicators can create a connection that resonates deeply with their audience, increasing the power of their message.

By understanding and ethically applying these principles, individuals and businesses can effectively navigate persuasive contexts and succeed in achieving their goals without damaging their reputations.

Robert Cialdini and Ethical Influence

Robert Cialdini has devoted much of his career to uncovering the science behind how people make decisions.

One of the critical aspects of Cialdini’s work is its focus on ethical influence. Rather than simply outlining manipulative tactics that can be employed by salespeople or marketers, his research provides valuable insights that help individuals better understand and defend against such techniques.

By studying the six original universal principles of influence – Reciprocity, Scarcity, Authority, Commitment and Consistency, Liking, and Consensus, Cialdini helps equip people with the knowledge to navigate the complex world of persuasion ethically and effectively.

In his later work Pre-suasion, where Cialdini introduced the seventh principle of influence: unity, he emphasizes the importance of shared identity and belonging in the process of persuasion.

When people feel a strong connection to a group or individual, they are more likely to be influenced by their opinions and actions. This principle has significant implications for cultivating relationships, reducing uncertainty, and motivating action in a variety of domains, from business to personal life.

Ethical influence is a cornerstone of Cialdini’s work, and it serves as a reminder that understanding and applying these principles should not be an exercise in manipulation.

Instead, by recognizing these natural aspects of human behaviour and decision-making, individuals can make more informed choices and avoid falling prey to persuasion tactics that may not align with their best interests.


In Robert Cialdini’s book, Influence: The Psychology of Persuasion, he dives deep into the psychological principles that govern human decision-making and behaviour. Throughout the book, he explores various universal principles and techniques, such as the contrast principle, reciprocation rule, and rejection-then-retreat technique. These methods play a significant role in influencing people’s actions in diverse situations, making them powerful weapons of influence.

One essential aspect that Cialdini emphasizes is the importance of responsibility in persuasion. By understanding and applying these psychological principles, one can make more informed decisions and navigate through social interactions with greater satisfaction. The foot-in-the-door technique, for example, relies on the understanding that making smaller, initial requests can lead to larger, more significant commitments in the long run.

Cialdini introduces the powerful concept of unity as the missing 7th element in his later book Pre-suasion. Unity encompasses the principle of connectedness and a shared identity among individuals. This element strengthens the bond between people, making it easier for them to comply with requests, as they feel a sense of belonging and loyalty towards each other.

Overall, Influence: The Psychology of Persuasion is a valuable resource for understanding the intricacies of human decision-making and the psychological underpinnings that drive our behaviour.

By learning and applying these universal principles and incorporating the notion of unity, individuals can become more mindful of their actions, making better decisions and forging stronger connections with others.

The friendly and accessible style of the book makes these complex concepts easy to grasp, ensuring that readers can implement these lessons in their day-to-day interactions and experiences.

Frequently Asked Questions

What are the main principles covered in Cialdini’s Influence?

In his book, Influence: The Psychology of Persuasion, Robert Cialdini covers six main principles: Reciprocity, Commitment and Consistency, Social Proof, Liking, Authority, and Scarcity. These principles help explain how and why people can be influenced by others in various situations.

How does the 7th element, Unity, fit in the persuasion framework?

The 7th element, Unity, was introduced by Cialdini in his later work and is not included in the original edition of Influence. In the context of persuasion, Unity refers to the shared identity and common goals between the influencer and the influenced. This principle suggests that people are more likely to be persuaded when they feel a sense of belonging with the person attempting to influence them.

Can you provide a chapter-wise summary of Influence: The Psychology of Persuasion?

Arizona State University provides a chapter-wise summary of Cialdini’s Influence. The summary covers all six principles and offers insights into each chapter’s content, making it a good resource for anyone interested in understanding the book’s key concepts.

What is the difference between the revised and expanded edition of Influence?

The revised and expanded edition of Influence includes updates and new examples to reflect recent developments and research in the field of persuasion.

How do the 7 principles of persuasion apply in real-life situations?

Cialdini’s principles of persuasion are applicable in various real-life scenarios, such as sales, marketing, negotiation, and interpersonal communication. For example, using the principle of Reciprocity in a business setting might involve offering a free sample to encourage customers to make a purchase. Similarly, Social Proof can be utilized through testimonials and reviews to build credibility for a product or service.

By understanding these principles, individuals can make better-informed decisions and recognize when persuasive techniques are being used on them.


Leave a Reply

Your email address will not be published. Required fields are marked *