A Review of Influence:
Robert B. Cialdini’s book Influence: New and Expanded (2021) presents 7 key principles of
persuasion, building on the original 6 from his classic work Influence: The Psychology of
Persuasion. Here's a summary of each principle:
1. Reciprocation
People feel obligated to return favors or concessions. When someone gives us something
or does a favor, we are more likely to comply with a subsequent request.
2. Liking
We’re more likely to say yes to people we like. Factors that increase liking include
physical attractiveness, similarity, compliments, and cooperative efforts.
3. Social Proof
People look to others to determine how to behave, especially in uncertain situations. If
others are doing it, we assume it’s the correct behavior.
4. Authority
We tend to follow the lead of credible, knowledgeable experts. Signals of authority
(titles, uniforms, etc.) can increase compliance.
5. Scarcity
Opportunities seem more valuable when they are limited or diminishing. The fear of
missing out (FOMO) can strongly drive decision-making.
6. Commitment and Consistency
Once people commit to something, especially publicly or in writing, they’re more likely
to follow through to stay consistent with that commitment.
7. Unity (New Principle)
People are more influenced by those they consider part of their tribe or identity group.
Shared identity—such as family, community, or values—enhances persuasion.