50 years of research. Thousands of papers. Summarized into 7 enduring principles of influence, each backed by landmark studies and world-leading researchers. 1. Reciprocity works. People are more likely to say yes when you offer something first. Referenced in: Dennis Regan’s classic 1971 study on reciprocity and compliance. 2. Social proof drives behavior. We look to others to decide what’s safe, credible, or desirable. Referenced in: Solomon Asch’s conformity experiments Robert Cialdini’s socia