Anchoring Bias
Category: Decision Making
The tendency to rely too heavily on the first piece of information offered (the 'anchor') when making decisions.
How it works
When your brain has to estimate an unknown quantity, it doesn't pull a number from thin air. It grabs the nearest available figure and adjusts from there. The problem is that the adjustment is almost always too small, you start at the anchor and stop short, leaving your final judgment tethered to whatever number you happened to see first.
This happens because estimation is effortful and the anchor offers a free starting point. Once a number is in your head, it activates related associations and quietly shifts what feels 'reasonable,' even when you know the anchor is arbitrary. Studies have shown people's estimates move toward an anchor produced by an obviously random spin of a wheel.
The effect is strongest when you're uncertain, rushed, or dealing with something hard to value, a salary, a house, a settlement, a rare object. The murkier the true value, the harder you grip the anchor.
Where you'll see it
- A recruiter asks your *current* salary before making an offer; that figure silently caps the new offer, which is exactly why a growing number of states have banned the question.
- A real-estate listing prices a home at $899,000; even buyers who think it's overpriced negotiate down to $850k instead of the $760k the comparables actually justify.
- A menu lists a $120 'chef's reserve' steak almost no one orders, its real job is to make the $60 steak feel like the sensible, mid-range choice.
Where it comes from
Anchoring was demonstrated by Amos Tversky and Daniel Kahneman in their landmark 1974 Science paper 'Judgment Under Uncertainty: Heuristics and Biases.' In their famous experiment, participants spun a rigged wheel of fortune (landing on 10 or 65) and then estimated the percentage of African nations in the UN, those who saw the higher number gave dramatically higher estimates, despite the spin being visibly random.
How to counter it
Generate your own number first. Before you look at the asking price, the suggested tip, or the opening offer, write down what you independently think the thing is worth. An anchor you've never seen can't move you.
Argue the opposite extreme. If a number feels high, deliberately brainstorm reasons the true value is far lower (and vice versa). This forces a bigger adjustment than your brain wants to make and pulls you off the anchor.
In negotiations, anchor first or reframe. Whoever names the first number sets the gravity. If you can't go first, refuse to treat their figure as the starting line, restate the problem in your own terms and bring your own comparables to the table.
The tell
You're doing it when your 'independent' estimate lands suspiciously close to the first number someone happened to show you.
Related biases
Featured in
- 7 cognitive biases that quietly wreck investors
- How to Actually Beat Your Cognitive Biases (Awareness Isn't Enough)
- Cognitive Bias vs. Logical Fallacy: What's the Difference?
- The 6 Biases Quietly Sabotaging Your Money
Common questions
What is Anchoring Bias?
Anchoring Bias is the tendency to rely too heavily on the first piece of information offered, known as the 'anchor,' when making decisions. Once that initial number or fact is in your mind, subsequent judgments stay tethered to it. It shapes estimates even when the anchor is arbitrary or irrelevant.
Why does Anchoring Bias happen?
Anchoring Bias happens because when your brain has to estimate an unknown quantity, it grabs the nearest available figure and adjusts from there rather than reasoning from scratch. The trouble is that the adjustment is almost always too small: you start at the anchor and stop short. This leaves your final judgment tethered to whatever number you happened to see first.
What is an example of Anchoring Bias?
A common example of Anchoring Bias is a recruiter asking your current salary before making a job offer. That figure silently caps the new offer, keeping it anchored to what you already earn rather than the role's true value. This effect is exactly why a growing number of states have banned the salary-history question.
How do you avoid Anchoring Bias?
To avoid Anchoring Bias, generate your own number first: before you look at the asking price, the suggested tip, or the opening offer, write down what you independently think the thing is worth. An anchor you have never seen cannot move you. You can also argue the opposite extreme, deliberately challenging a number that feels high.
What is the difference between Anchoring Bias and the Framing Effect?
Anchoring Bias is about a specific starting number or value that pulls your estimate toward it, so your final judgment stays tethered to the first figure you saw. The Framing Effect, by contrast, is about how the presentation or wording of the same information (such as '90 percent survival' versus '10 percent mortality') changes your choice. Anchoring hinges on a reference number, while framing hinges on how equivalent facts are described.
References
- Tversky, A., & Kahneman, D. (1974). Judgment under Uncertainty: Heuristics and Biases. Science, 185(4157), 1124-1131
- Jacowitz, K. E., & Kahneman, D. (1995). Measures of Anchoring in Estimation Tasks. Personality and Social Psychology Bulletin, 21(11), 1161-1166
- Strack, F., & Mussweiler, T. (1997). Explaining the Enigmatic Anchoring Effect: Mechanisms of Selective Accessibility. Journal of Personality and Social Psychology, 73(3), 437-446
- Epley, N., & Gilovich, T. (2006). The Anchoring-and-Adjustment Heuristic: Why the Adjustments Are Insufficient. Psychological Science, 17(4), 311-318
- Schley, D. R., & Weingarten, E. (2026). Fifty Years of Anchoring Effects: A Theoretical Reintegration and Meta-Analysis. Management Science (Articles in Advance)