Influence: The Psychology of Persuasion

Cialdini's book catalogues six principles of influence — reciprocity, commitment, social proof, liking, authority, scarcity — and illustrates each with research and specific cases. The book has become the canonical reference on persuasion psychology for practitioners, and its influence on contemporary marketing and product design is enormous (sometimes appallingly so). For product direction it is required reading in both directions: the mechanisms Cialdini describes are the ones used to persuade you and the ones product teams use on users. Reading it carefully exposes dark patterns as clearly as legitimate persuasion, which is useful. The updated editions add material on a seventh principle (unity) and on the responsibilities of the persuader.