The anchoring effect is a cognitive bias where an initial piece of information, even if arbitrary, disproportionately influences your subsequent judgments and decisions. If someone mentions a number before you make an estimate, your final answer will drift toward that number, whether or not it was relevant. It is one of the most robust and well-documented biases in psychology, affecting everything from salary negotiations to jury verdicts to how much you’re willing to pay for a sweater.
How Anchoring Works
The core mechanism is surprisingly simple. When you encounter a number or value before making a judgment, your brain uses it as a starting point and then adjusts from there. The problem is that the adjustment is almost always insufficient. You don’t move far enough away from the anchor, so your final estimate stays biased toward it.
This process, known as “anchor and adjust,” was first described by psychologists Amos Tversky and Daniel Kahneman in 1974. In their landmark experiment, participants spun a rigged wheel of fortune that landed on either 10 or 65. They were then asked to estimate what percentage of United Nations member countries were African. People who saw the number 10 guessed around 25%. People who saw 65 guessed around 45%. A completely random number from a wheel of fortune shifted their estimates by 20 percentage points.
The anchor doesn’t need to be meaningful. It doesn’t need to come from a credible source. It just needs to be present in your mind before you form a judgment. That’s what makes the effect so powerful and, frankly, so unsettling.
Anchoring in Negotiation
Negotiation is where anchoring has the most direct, measurable financial consequences. Research consistently shows that the person who makes the first offer tends to achieve better outcomes, because that initial number becomes the anchor around which the rest of the negotiation revolves. A high opening ask from a seller pulls the buyer’s counteroffers upward. A low opening bid from a buyer drags the seller’s expectations down.
A 2015 study from Columbia University found that sellers can amplify this effect by presenting a range rather than a single number, as long as the range starts at their ideal price and goes higher. Buyers who received these “bolstering range” offers made larger concessions and submitted more generous counteroffers. They also assumed the seller had a higher minimum acceptable price, which shifted the entire negotiation in the seller’s favor. If you’ve ever wondered why the first number in a salary discussion feels like it sets the ceiling or floor for everything that follows, this is why.
How Retailers Use Price Anchors
Every “was $120, now $79” tag you’ve ever seen is an anchoring strategy. The original price exists not as useful historical information but as a reference point that makes the sale price feel like a bargain. Research in consumer psychology confirms the mechanism: when shoppers judge whether a current price is reasonable, they automatically compare it to whatever reference value is available. A high anchor produces a higher price estimate, and a low anchor produces a lower one.
Retailers exploit this by placing expensive items next to moderately priced ones, listing inflated “original” prices on clearance racks, or surrounding a target product with higher-priced alternatives. The goal is to create a high-anchor environment so that the price you actually pay feels low by comparison. You’re not evaluating the product’s value in isolation. You’re evaluating it relative to the anchor that was placed in front of you.
Anchoring in the Courtroom
The legal system is particularly vulnerable. When a plaintiff’s attorney asks a jury to award $5 million in pain and suffering damages, that number anchors the jury’s deliberation, regardless of the actual evidence. Studies using jury simulations have tested this directly: when the plaintiff demanded $5 million instead of $250,000 in non-economic damages, the overall expected value of the case rose dramatically.
One widely cited finding in this area put it bluntly: “the more you ask for, the more you get.” Researchers also found that high anchors were extremely difficult for defense attorneys to counter. None of the defense strategies tested, including presenting a lower counter-anchor, effectively neutralized a plaintiff’s high demand. This has real implications for the fairness of jury decisions, especially in cases involving subjective damages like pain and suffering where there’s no objective standard to fall back on.
Experts Are Not Immune
One of the most counterintuitive findings in anchoring research is that expertise offers little protection. In a well-known 1987 study, real estate agents were given listing prices for properties and asked to appraise them. The listing prices were manipulated to be artificially high or low. The agents’ valuations shifted with the anchors, just as non-experts’ did. Most of the agents denied being influenced by the listing price, insisting they used objective criteria. They were wrong.
This pattern repeats across professions. Judges, doctors, financial analysts, and engineers all show anchoring effects in their areas of expertise. Domain knowledge helps you generate better estimates on average, but it doesn’t prevent the gravitational pull of an irrelevant number.
What Makes Anchoring Stronger
Several conditions amplify the bias. Time pressure makes it worse, because you have less opportunity to adjust away from the anchor. Cognitive load (being mentally distracted or overwhelmed) has the same effect. Even alcohol consumption reduces adjustment, which makes sense given that moving away from an anchor requires effortful thinking.
Your emotional and physiological state matters too. Research published in Psychological Science found that people under psychological threat showed less adjustment from anchors than those in a calmer, more confident state. Participants whose bodies responded to stress with increased vascular resistance and decreased cardiac output (a “threat” response) adjusted less than those whose bodies responded with a “challenge” pattern. In practical terms, if you’re anxious, fatigued, or feeling pressured, you’re more susceptible to being anchored.
How to Reduce the Anchoring Effect
The most studied debiasing technique is called “consider the opposite.” Instead of accepting an anchor and adjusting from it, you deliberately generate reasons why the anchor might be wrong. If a seller quotes $500,000 for a property, you force yourself to list specific reasons it might be worth less. This technique has been shown to significantly reduce anchoring, particularly when the anchor is high. In one study, participants who used the consider-the-opposite approach gave evaluations roughly 7-8% lower than those who were exposed to the same high anchor without the technique.
There’s a catch, though. The consider-the-opposite technique works asymmetrically. It is effective at pulling people down from high anchors, but it doesn’t reliably push people up from low anchors. Researchers have found no significant debiasing effect when the anchor is low, which suggests that the strategy works by creating friction against inflated estimates rather than correcting all forms of anchoring equally.
Beyond that specific technique, the most practical defense is simply awareness combined with independent research. Before entering a negotiation, appraisal, or any situation where numbers will be thrown around, generate your own estimate first. Consult multiple data sources. Write down your valuation before you hear anyone else’s. The anchor is most dangerous when it fills a vacuum. If you already have a well-reasoned number in mind, the external anchor has less empty space to occupy.