The deep, near-involuntary compulsion to return favors — and disfavors — often in disproportion to what was given.
"The automatic tendency of humans to reciprocate both favors and disfavors has long been noticed as extreme, and can be very useful in gaining cooperation from other persons... And the same reciprocation tendency works with disfavors. This is one of the main reasons why civilization has created criminal law and courts."
A free sample, an unsolicited favor, a first concession in a negotiation — the trigger costs the giver little.
The mind registers an unpaid debt. Discomfort persists — social, evolutionary wiring — until the ledger feels balanced.
Compliance, a purchase, a concession, or — mirrored in reverse — an escalating retaliation, feud, or vendetta.
Fuller Brush and Electrolux salesmen built entire door-to-door businesses on leaving a small free gift before pitching. The prospect's felt debt did the closing.
Robert Cialdini's "rejection-then-retreat" technique: open with an inflated ask, then concede to the real target. The other party feels obliged to reciprocate with a concession of their own.
In Axelrod's computer tournaments, the simplest reciprocation-based strategy — cooperate first, then mirror the opponent's last move — outperformed every more "clever" algorithm entered.
Separate the gift from the decision. Ask: "Would I still choose this if the favor had never been offered?"
Munger's rule: treat unsolicited favors from those seeking your money or vote with heightened, not lowered, suspicion.
In negotiation, recognize the "extreme-anchor-then-concession" pattern by name — naming a bias disarms much of its power.
On the negative side, build in a deliberate delay before retaliating. Courts and cooling-off periods exist precisely to interrupt the reciprocation reflex.
Remember it compounds with other tendencies — liking, authority, social proof — into Lollapalooza effects. A trusted, liked authority's small gift is far harder to resist than a stranger's.
"Bad behavior by one person often triggers bad behavior in another... reciprocation, roughly automatic on the part of the recipient, occurs whether the favor or disfavor is deserved or not."