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The Influence Room · The six principles

Six levers — and they are not equal

Last reviewed: July 2026
The short answer

The famous six principles of influence — reciprocity, commitment, social proof, authority, liking, scarcity — are usually presented as six equivalent laws. They are not. Reciprocity, commitment and social proof have strong support; authority and liking are real but more variable; and scarcity effects are the shakiest, being highly context-dependent and easily backfiring.

Six levers — and how firm each one is
RECIPROCITYsolid COMMITMENTsolid SOCIAL PROOFsolid AUTHORITYpromising LIKINGpromising SCARCITYcontested
They are usually sold as six equal laws. They are not.

What each one actually is

  • Reciprocity — receive something, feel obliged to give back. Powerful even when the gift was unrequested and worthless. The free sample is not generosity; it is an opening move.
  • Commitment & consistency — once you take a small step, you act to stay consistent with it. This is the foot in the door, and it is quietly the strongest of the six.
  • Social proof — you copy others, especially when uncertain or when they resemble you.
  • Authority — you defer to perceived expertise and its symbols — the title, the uniform, the white coat. Real, but see how badly the famous study is misread.
  • Liking — you say yes to people you like, find attractive, or see as similar. Which is why the salesperson mentions they also have a labrador.
  • Scarcity — you want what is limited. Genuinely effective in some contexts, and obviously fake urgency now often produces suspicion and backfire, particularly online. See the honest page.
Why they work at all

Every one is a useful shortcut in normal life. Reciprocity holds societies together. Copying others is usually smart. Deferring to experts is efficient. Wanting rare things tracks real value.

The shortcuts are not flaws — they are features, and that is precisely why they are exploitable. A persuader does not install anything new in you. They simply press a button you already have.

The honest caveat about this whole field

Much of classic social psychology took heavy damage in the replication crisis. Some influence effects hold up robustly; others are smaller, more fragile, or more context-dependent than the bestselling books imply. Anyone presenting all six as iron laws with equal footing is selling a book, not reporting a literature.

Keep going

More from this wing: all 8 pages · related: manipulation tactics, the bias explorer, friction.

Frequently asked

What are the six principles of influence?
Reciprocity, commitment and consistency, social proof, authority, liking, and scarcity — popularised by Robert Cialdini.
Are all six principles equally well supported?
No. Reciprocity, commitment and social proof have strong support; authority and liking are real but more variable; scarcity effects are the most contested and can backfire.
Why do influence techniques work on us?
Because they exploit shortcuts that normally serve us well — reciprocity sustains cooperation, copying others is usually sensible, and deferring to experts is efficient. Persuaders press buttons you already have.

Sources & further reading

  1. Cialdini’s principles, summary — reciprocity, commitment/consistency, social proof, authority, liking, scarcity — are drawn from decades of compliance research, including his own door-in-the-face experiments (1975). Cialdini’s principles, summary ↗
  2. Read any influence claim with the replication record in mind: the Open Science Collaboration (2015) found only 36% of 100 replications significant against 97% of originals — social psychology fared worse than cognitive. Compliance techniques held up better than priming effects, but treat dramatic single studies with caution. Reproducibility Project, 2015 ↗
  3. Multiple meta-analyses (Beaman et al., 1983; Dillard, Hunter & Burgoon, 1984; Fern, Monroe & Avila, 1986) confirm foot-in-the-door and door-in-the-face work — while showing the effects are modest and condition-dependent, not magic. Compliance meta-analyses, archived PDF ↗

Educational content, not professional advice. Last reviewed July 2026.