Psychology › Thinking, memory & biases › Heuristics and biases
Anchoring
1974· Finding or experiment
Well replicatedStrong, repeated evidence.
Anchoring is the pull of a first number on later estimates, even when that number is obviously arbitrary.
See it on the Psychology map →What it says
In 1974 Tversky and Kahneman spun a rigged wheel that stopped at 10 or 65, then asked people what percentage of African nations were in the UN. Median answers were 25 and 45. In a 1987 study by Gregory Northcraft and Margaret Neale, real-estate agents appraising the same house gave higher values when shown a higher listing price, while denying it influenced them. First offers in negotiations work the same way.
Why it matters
It shapes prices, salaries, settlements and appraisals. It is why experienced negotiators often open first and counter extreme anchors immediately.
Think of it like
Like a listing price: even buyers who think it inflated end up negotiating around it.
The evidence
Well replicated. Anchoring produced some of the strongest effects in the 2014 Many Labs project, though anchors that are plainly meaningless have smaller effects than early studies suggested.
Open questions
Why it happens is debated: too little adjustment away from the anchor, or the anchor bringing matching facts to mind. Both probably play a part.
Connections (2)
▸Anchoring is one of the original Heuristics and biasesWell replicated
The connection
Anchoring and adjustment was the third heuristic in the 1974 Science paper: people start from an available number and adjust, but not enough. Unlike the other two, it concerns numerical estimates, and it became one of the program's most reliable and widely applied findings.
Who showed it and when
Tversky and Kahneman, 1974, using the rigged wheel and a quick-multiplication test: 8×7×6×5×4×3×2×1 drew higher estimates than the same numbers in ascending order.
The evidence
The 1974 paper's experiments, and large replications such as Many Labs (2014), where anchoring produced some of the strongest effects.
Open questions
Whether anchoring is truly 'insufficient adjustment' or something else, such as the anchor priming consistent information, remains unresolved.
▸Anchoring shapes negotiations studied in Behavioral economicsWell replicated
The connection
Behavioral economists use anchoring to explain why first offers, listing prices and suggested retail prices move final deals. In negotiation studies, the side making the first offer often ends closer to it. A 2003 study found arbitrary numbers, like Social Security digits, swayed what people would pay.
Who showed it and when
Northcraft and Neale's 1987 appraisal study with Tucson real-estate agents; Adam Galinsky and Thomas Mussweiler on first offers (2001); Dan Ariely and colleagues at MIT (2003).
The evidence
Lab negotiations, real-estate data, and field studies of prices and even judges' sentencing show anchors shifting outcomes.
Open questions
Arbitrary anchors like Social Security digits replicated weakly in 2014; anchors that look relevant, like asking prices, are much more robust.