Anchoring bias: why the first number you hear hijacks your judgment

In a classic study, Tversky and Kahneman spun a rigged wheel that landed on either 10 or 65, then asked participants to estimate the percentage of African countries in the UN. Those who saw 65 guessed 45% on average. Those who saw 10 guessed 25%. A random number had shifted their estimates by 20 points.

Anchoring works because our brains use the first available number as a reference point and adjust insufficiently from there. This isn't laziness — it's how neural networks economize on computation. The anchor activates related concepts and primes a range of "reasonable" values.

In daily life, anchors are everywhere: the "original price" crossed out on a sale tag, the first salary number mentioned in a negotiation, the suggested tip percentages on a receipt. The defense isn't ignoring anchors — it's generating your own anchor first before encountering others.