
Anchoring bias describes people’s tendency to rely too heavily on the first piece of information they receive on a topic. Regardless of the accuracy of that information, people use it as a reference point, or anchor, to make subsequent judgments. Because of this, anchoring bias can lead to poor decisions in various contexts, such as salary negotiations, medical diagnoses, and purchases.
Example: Anchoring bias
You are considering buying a used car, and you visit a car dealership. The dealer walks you around, showing you all the higher-priced cars, and you start worrying that you can’t afford a car after all.
Next, the car dealer walks you toward the back of the lot, where you see more affordable cars. Having seen all the expensive options, you think these cars seem like a good bargain. In reality, all the cars are overpriced. By showing you all the expensive cars first, the dealer has set an anchor, influencing your perception of the value of a used car.
Anchoring bias (also known as anchoring heuristic or anchoring effect) is a type of cognitive bias that causes people to favor information they receive early in the decision-making process. People hold on to this information, called an anchor, as a reference point and fail to correctly adjust their initial impressions, even after receiving additional information.
Once the anchor is set, subsequent judgments are made by adjusting away from that anchor, while staying within the range set by it. For example, the initial price offered for a used car sets the standard for the rest of the negotiation. Here, prices lower than the initial price seems like a good deal, even if they are still higher than the car’s actual value. As a result, our perception of reality is distorted, and our decisions are biased.
Depending on their sources, anchors can be external or internal.
Note
It is important to keep in mind that the more knowledgeable we are about a certain topic, the less likely we are to fall for anchoring bias. When we don’t have enough information to know how to value something, we are more likely to be influenced by anchors.
Although there is no consensus as to why anchoring bias happens, two mechanisms can help explain this phenomenon:
Anchoring and adjustment is the mechanism that explains how people try to answer a general knowledge question when they don’t know the answer.
Example: Anchoring and adjustment
Suppose you need to answer the question “How long does it take Mars to orbit the Sun?” but don’t know the correct answer and you’re not allowed to search for it online! You remember that Mars is between Earth and Jupiter and that it takes 12 years for Jupiter to orbit the Sun.
Based on this, you estimate that the correct answer is somewhere close to 12 years. After thinking some more, you come up with your final answer: 6 years. Unfortunately, your internal anchor (12 years) was too high, and it didn’t allow you to adjust sufficiently so as to approximate the correct answer, which is actually 1.88 years.
When we are presented with an external anchor, our first response is to consider the anchor as a possible answer. While we are doing that, we activate existing information in our brain that is consistent with the anchor.
Example: Selective accessibility
When asked whether Mahatma Gandhi was younger or older than 86 when he died, people often engage in confirmatory hypothesis testing. In other words, they are influenced by the phrasing of the question and recall information that supports the hypothesis presented to them: that Gandhi was approximately 86 years old when he died. As a result, this information is likely to influence their final answer.
This selective accessibility mechanism works even when anchors are clearly unrealistic. When asked whether Mahatma Gandhi was
or
participants were influenced by these implausible anchors.
Participants who received the high implausible anchor estimated on average that Gandhi lived 67 years, whereas participants who received the low implausible anchor thought that he was just 50 years old when he died.
Salary negotiations are particularly susceptible to anchoring bias. The person who opens the negotiations and sets the anchor has an advantage.
Example: Anchoring bias and salary negotiations
You have passed the first round of interviews for a job, and you are now invited to a second round. During a call, the HR person makes you an offer of $50,000 per year. Considering the role and your previous experience, you know this is too low of an offer.
With that amount as a starting point, you manage to negotiate up to $55,000. You are satisfied that you got more than they initially offered. In reality, the HR person could have offered you more, but they used the anchoring effect against you. By starting with a low value, they influenced your perception of what an acceptable salary would be.
Anchors that are entirely arbitrary and unrelated to the decision can still influence our judgment, especially when we lack the knowledge to make an educated guess.
Example: Anchoring bias and random anchors
In an experiment, participants were asked to estimate the percentage of African countries in the United Nations (UN) in two ways:
Even though the anchor was entirely arbitrary and irrelevant to the question, it still influenced participants who used it as a standard in their subsequent judgment. As a result, their answers were close to the anchor. For example:
This shows that under the anchoring bias, irrelevant anchors are just as impactful as anchors that offer relevant informational cues.
Apart from anchoring bias, there are two more types of heuristics that people use that can affect their decision-making:
Although all of them help us reduce the time and effort needed to form a judgment, they do so in different ways.