Overview
Robert Cialdini identifies six universal principles of influence that explain why people say yes. Based on thirty-five years of evidence-based research, he reveals the psychology behind compliance and shows how to apply these insights ethically — and how to defend yourself against manipulation.
Cialdini is a social psychologist at Arizona State who spent three years training as a car salesman, fundraiser, and advertiser in order to understand persuasion from the inside. Influence, first published in 1984 and regularly updated since, catalogues six weapons of influence — reciprocation, commitment, social proof, liking, authority, and scarcity — with a seventh (unity) added in a later edition.
Key Ideas
Reciprocity
People feel obligated to return favors, even uninvited ones.
Scarcity
Things seem more valuable when they are less available.
Social proof
People look to others' actions to determine their own, especially in uncertain situations.
Authority
People defer to experts and those in positions of authority, even when they shouldn't.
Commitment and consistency
Once people commit to something, they are more likely to follow through to remain consistent.
Who should read this
Anyone who buys things, sells things, or is ever asked for anything. The book is valuable both offensively — if you need to persuade — and defensively — if you don't want to be persuaded against your own interests. The chapter on commitment and consistency explains more political and consumer behaviour than any other single framework I know.
Who might skip it
Skip if you've already internalised the six principles through business or marketing training — the original is still the best version, but you may not need it. Skip also if you dislike the 'compliance professional' anecdotes; some of them now feel dated.
The verdict
One of the ten or so non-fiction books I think every adult should read. Cialdini's frameworks are specific enough to be useful, general enough to apply across contexts, and honest enough that you finish the book less manipulable than when you started. The revised and expanded edition is the one to get.
"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."
— Robert B. Cialdini, Influence: The Psychology of Persuasion
If you liked this
Pre-Suasion, Cialdini's follow-up. For related ground with different angles, Yes! by Noah Goldstein (also with Cialdini).