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Kantian Fairness Tendency: people will reject unfair offers even at personal cost, and extend extra cooperation when treated fairly.

Kantian Fairness Tendency
Topic #17 · Psychology & Human Misjudgment · Poor Charlie's Almanack
Core mechanic
The feeling
Humans have a near-moral, visceral sense of what constitutes a fair deal — and will sacrifice real value to punish violations of it.
The origin
Kant's categorical imperative: act only on principles you'd universalize. Evolutionary roots: fair resource-sharing in tribal groups was survival-critical.
The ultimatum game — rationality vs. fairness
Proposer
$70 / $30 split
▶
Responder
Accept → both profit Reject → both get $0
Rational prediction: accept any offer > $0. Observed reality: offers below ~30% are routinely rejected.
Coca-Cola
Dynamic pricing (hot weather)
▶
Public
Outrage — abandoned
Economically sound. Socially catastrophic. The exploitation feeling when thirsty overwhelmed the price signal.
The tendency cuts both ways
⚖
Fairness perceived → surplus cooperation
  • Partners do more than the contract requires
  • Employees exercise discretionary effort
  • Customers extend loyalty beyond price
  • Negotiating counterparties move faster
✗
Fairness violated → irrational punishment
  • Rational deals rejected at personal cost
  • Lifetime customer relationships destroyed
  • Skilled employees quit below-market offers
  • Lawsuits filed that cost more than the dispute
Pre-deal fairness audit
1
Switch seats mentally. From their side of the table, does this deal read as exploitation — or mutual gain?
2
Audit the opening offer. An anchor so low it signals contempt will poison the entire process, even if you later move to a fair number.
3
Show your reasoning. Unexplained terms feel arbitrary and unfair. Explained terms — even tight ones — feel legitimate.
4
Price disguise ≠ price fairness. Airlines hide disparity via "fare classes." If discovery would trigger rage, the deal may still be structurally unfair.
"A man who is not fair does not deserve to be trusted. And once you've lost the trust of your partners, the deal you saved turns out not to have been worth saving."
— Charlie Munger, paraphrased from Poor Charlie's Almanack