Cialdini’s Principles of Influence

The six levers of persuasion, the mechanism behind each, and how to use them honestly

What are Robert Cialdini’s six principles of influence and persuasion?

Robert Cialdini identified six near-universal levers of persuasion — reciprocity, commitment and consistency, social proof, authority, liking, and scarcity — that bias people toward saying yes. They’re drawn from decades of social-psychology research and field studies; the principles are well established even though individual effect sizes vary by context.

Cialdini’s premise is that most decisions run on mental shortcuts — heuristics that usually serve us but can be triggered to manufacture compliance. Knowing the levers does double duty: it makes your honest asks land, and it inoculates you against manipulation. Below are the six principles, each explained by the cognitive shortcut it exploits and graded on how strong the underlying research is.