Our Review
The book that defined persuasion science — now with a seventh principle added 35 years later.
What it's about
Influence, New and Expanded is the 2021 updated edition of Robert Cialdini's foundational text on persuasion psychology, first published in 1984. The book identifies and explains the seven principles through which people are reliably moved to say yes: Reciprocity, Commitment and Consistency, Social Proof, Authority, Liking, Scarcity, and — new in this edition — Unity. Each principle is grounded in decades of social psychology research and illustrated with real-world experiments, case studies from business and marketing, and examples of how the principles operate in everyday interactions. The expanded edition updates the science throughout and adds the Unity chapter, which Cialdini considers the most important principle he had originally missed.
Narration
Cialdini narrates his own book — dry and academic by design, but authoritative in a way that matters. You are hearing the researcher explain his own decades of work, not a voice actor interpreting it. The pacing is measured and clear. At 13 hours it is a long listen, but each chapter covers one principle thoroughly before moving to the next, making it easy to pause between principles.
Who it's for
Anyone in a role that involves persuasion — sales, marketing, negotiation, management, fundraising — and anyone who wants to understand how influence operates on them in daily life. Cialdini designed the book to serve both purposes: understanding how to ethically apply these principles and how to recognize and resist them when used against you.
Who should skip it
Listeners who read the original Influence recently. The new content in this edition — primarily the Unity chapter and updated research citations — represents roughly 20% of the total material. If you are already familiar with the six original principles, decide whether a full 13-hour re-listen is the best use of your credit.
Verdict
Listen to it. The definitive version of the most important persuasion book ever written. The Unity chapter alone justifies the expanded edition over the original.
Pros & Cons
Pros
- Narrated by Cialdini himself — the source, not an interpreter
- 2021 expanded edition adds the seventh principle (Unity) and new research throughout
- Every principle is illustrated with real experiments and case studies, not anecdotes
Cons
- 13 hours is a commitment — denser than most business audiobooks
- Some research examples are dated (though the 2021 edition updated many)
- Overlaps significantly with the original Influence — if you've read that, check what's new first
Verdict
Listen to it.
The expanded edition is the definitive version. If you have only read the original, the Unity chapter alone is worth returning for.
Bottom Line
The foundational text on persuasion psychology. Seven principles, decades of research, narrated by Cialdini. The 2021 edition adds Unity as the seventh principle and updates the science throughout.
Frequently Asked Questions
What is the difference between Influence and Influence New and Expanded?
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The 2021 expanded edition adds a seventh principle — Unity (the sense of shared identity) — and updates many examples and research citations throughout. The original had six principles. If you haven't read either, start with this version.
What are the seven principles of influence?
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Reciprocity, Commitment and Consistency, Social Proof, Authority, Liking, Scarcity, and Unity (the new seventh principle added in the 2021 edition).
Who narrates Influence New and Expanded?
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Robert Cialdini narrates his own book. His delivery is measured and academic — clear, precise, and authoritative. Not the most dynamic narration on Audible, but hearing the author explain his own research adds credibility.
Is Influence worth reading after Never Split the Difference?
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Yes — they complement each other. Never Split the Difference is tactical and conversational; Influence is scientific and structural. Understanding the principles in Influence makes the tactics in Voss's book more powerful.
How long is the audiobook?
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13 hours 2 minutes. Longer than most business books — plan for two weeks of commutes or four to five workout sessions.