This is a Lexicon entry: the mechanism, when it shows up, and the countermeasure. The full correction, with real-world cases and the audit prompt, hasn't been written yet.
Definition
The tendency to compare all subsequent information to the very first piece of information received, even when that first number is arbitrary.
When it shows up
Any negotiation where a number is named first. Receiving an initial estimate, quote or asking price. Exposure to any number, even one you know is arbitrary, before forming your own estimate. Modern context: A negotiation opens with a deliberately extreme initial offer. The final agreed number, even after extensive counteroffers, remains significantly closer to the extreme anchor than to either party's actual reservation price. High-stakes instance: Legal sentencing - documented studies show that arbitrary sentencing anchors (including those generated by dice rolls) influence judicial sentence length estimates, with adjustments from the anchor being systematically insufficient. Failure mode: Subsequent judgments are pulled toward the initial number. Adjustments from the anchor are systematically too small, even when the anchor is explicitly arbitrary or known to be wrong. The anchor sets the scale the mind works in. Estimated cost: High - often irreversible where this bias dominates unchecked decisions.
Failure mode
Subsequent judgments are pulled toward the initial number. Adjustments from the anchor are systematically too small, even when the anchor is explicitly arbitrary or known to be wrong. The anchor sets the scale the mind works in.
Countermeasure
Generate your own estimate before hearing any external number. When anchored, explicitly overshoot the adjustment: research shows people under-adjust so force yourself past where it 'feels right'. When correction costs more than the bias: When the anchor carries genuine information from a credible source. Expert valuations, regulatory benchmarks and market prices are anchors that encode real signal. The correction applies to arbitrary, uninformative anchors - not to all anchors.
Related traps
Also connected in the map10 more, locked
Credit & first seen
DiscoveredMcGlone, M.S.&Tofighbakhsh, J. (2000).'Birds of a feather flock conjointly (?): Rhyme as reason in aphorisms.'Psychological Science 11(5), 424-428 source ↗
Also revealed
Entry #57 of 631 in The Lexicon · see the full Lexicon