The anchoring effect occurs when people consider a number before estimating an unknown quantity — and stay near that number even when the anchor is obviously irrelevant. Kahneman and Tversky's wheel-of-fortune study (10 vs 65) moved UN membership estimates for African nations from 25% to 45%.
Two mechanisms
Adjustment (System 2): start from anchor, adjust insufficiently, stop when tired.
Priming (System 1): exposure to a number activates associative machinery; no deliberate adjustment.
Both operate. Listing prices anchor buyers; Gandhi-age questions anchor age estimates; first offers anchor negotiations.
What to do
- Treat any salient number as a potential anchor — "this number will anchor us."
- In negotiations, make the first offer when you have information; resist others' anchors when you do not.
- Use high/low anchors consciously only when ethical.