The Unity Principle (Cialdini)
The 7th persuasion lever: people say yes to whoever feels like "us," not just "like me."
Grounded in the research on Robert Cialdini (Wikipedia) — "Pre-Suasion" / principles of persuasion; Unity
Where it came from
Robert Cialdini wrote the 1984 book Influence and named 6 persuasion principles: reciprocity, commitment, social proof, authority, liking, scarcity. In 2016's Pre-Suasion he added a 7th: Unity. Liking is 'this person is like me.' Unity is heavier: 'this person is OF me' — same shared identity, same category, same we. Not similarity, shared self.
The mechanism
Unity exploits how the brain merges 'self' and 'in-group.' When someone is tagged as 'one of us' — family, hometown, team, nation, faith — your brain processes their interests using overlapping neural circuitry to your own. So you weight their requests like they're partly yours. It's identity-fusion, not friendship. The cue triggers the bias automatically, before you reason about it.