How Hindsight Bias Affects How We View the Past

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Have you ever noticed that events seem more predictable after they have already happened? The results of an election, for example, often seem more obvious after the tallies have been counted. They say that hindsight is 20/20. In other words, things always seem more obvious and predictable after they have already happened.

In psychology, this is what is referred to as the hindsight bias. This bias can have a major impact on not only your beliefs but also on your behaviors.

This article takes a closer look at how the hindsight bias works. It also explores how it might influence some of the beliefs you hold as well as the decisions you make on a day-to-day basis. 

What Is Hindsight Bias?

The term "hindsight bias" refers to the tendency people have to view events as more predictable than they really are. Before an event takes place, while you might be able to offer a guess as to the outcome, there is really no way to actually know what's going to happen. 

After an event, people often believe that they knew the outcome of the event before it actually happened. This is why it is often referred to as the "I knew it all along" phenomenon.

For example, after a person's favorite team loses the Super Bowl, they might feel convinced that they knew the team was going to lose (even though they didn't feel that way before the game). The phenomenon has been demonstrated in a number of different situations, including politics and sporting events. In experiments, people often recall their predictions before the event as much stronger than they actually were.

Examples of Hindsight Bias

Researchers Dorothee Dietrich and Matthew Olson asked college students to predict how the U.S. Senate would vote on the confirmation of Supreme Court nominee Clarence Thomas. Prior to the Senate vote, 58% of the participants predicted that he would be confirmed. When students were polled again after Thomas was confirmed, 78% of the participants said that they thought Thomas would be approved.

The hindsight bias involves the tendency people have to assume that they knew the outcome of an event after the outcome has already been determined.

For example, after attending a baseball game, you might insist that you knew that the winning team was going to win beforehand. High school and college students often experience hindsight bias during the course of their studies.

As they read their course texts, the information may seem easy. "Of course," students often think after reading the results of a study or experiment. "I knew that all along."

This can be a dangerous habit for students to fall into, however, particularly when test time approaches. By assuming that they already knew the information, they might fail to adequately study the material.

When it comes to testing time, however, the presence of many different answers on a multiple-choice test may make many students realize that they did not know the material quite as well as they thought they did. By being aware of this potential problem, however, students can develop good study habits to overcome the tendency to assume that they "knew it all along."


Examples of the hindsight bias include a person believing they predicted who would win an election or sporting event. Students might assume that they could predict the questions and answers on exams, which can affect how much effort they devote to studying.

Causes of Hindsight Bias

So what exactly causes this bias to happen? Researchers suggest that three key variables interact to contribute to this tendency to see things as more predictable than they really are.

  • Cognitive: People tend to distort or even misremember their earlier predictions about an event. It may be easier to recall information that is consistent with their current knowledge.
  • Metacognitive: When people can easily understand how or why an event happened, that event can seem like it was easily foreseeable.
  • Motivational: People like to think of the world as a predictable place. Believing an outcome was inevitable can be comforting for some people.

When all three of these factors occur readily in a situation, the hindsight bias is more likely to occur.

When a movie reaches its end and the viewer discovers who the killer really was, they might look back on their memory of the film and misremember their initial impressions of the guilty character.

They might also look at all the situations and secondary characters and believe that given these variables, it was clear what was going to happen. So they might walk away from the film thinking that they knew the outcome all along, but the reality is that they probably didn't.

Impact of Hindsight Bias

One potential problem with this way of thinking is that it can lead to overconfidence. If people mistakenly believe that they have exceptional foresight or intuition, they might become too confident and more likely to take unnecessary risks.

Such risks might be financial, such as placing too much of your nest egg in a risky stock portfolio. They might also be emotional, such as investing too much of yourself in a bad relationship. 

Blaming the victim is another possible effect of hindsight bias. People often believe that since they "knew" what was going to happen all along (because of hindsight bias), the victim of a crime, accident, or other tragedy should have also been able to easily predict the outcome.


Hindsight bias can lead to overconfidence in your ability to predict what is going to happen. This can lead to poor decision-making and can affect how you assign blame for events.

Overcoming Hindsight Bias

Is there anything that you can do to counteract the hindsight bias? There are a number of tactics you might try in order to reduce how this bias influences your thoughts and behaviors:

  • Consider alternative outcomes: Researchers suggest that one way to counteract this bias is to consider things that might have happened but didn't. By mentally reviewing potential outcomes, people might gain a more balanced view of an outcome's apparent inevitability.
  • Keep a decision journal: Writing down your thinking about a problem and solution is one way to minimize the effects of hindsight bias. Instead of looking back and believing that you knew the answer all along, a journal means you'll have a written record of your thinking process as you worked through a specific problem.
  • Remember your original judgments: Research suggests that intentionally retrieving the memory of your original judgment before you recall the correct outcome can be helpful for eliminating hindsight bias.


Reducing hindsight bias isn't always easy, but there are steps that you can take to minimize its effects. Considering alternatives, consciously remembering your earlier predictions, and keeping a decision journal are a few strategies that might help.

A Word From Verywell

The hindsight bias is very common, but that doesn't mean that it doesn't have negative effects on how you think about past events. Believing that you knew the outcome all along can lead to an overreliance on the accuracy of your own predictions.

In order to minimize the hindsight bias, you might try keeping a decision journal or thinking of alternative outcomes that also might have happened. By taking steps to prevent hindsight bias, you can help improve the accuracy of your judgments.

5 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Dietrich D, Olson M. A demonstration of hindsight bias using the Thomas confirmation vote. Psychol Rep. 1993;72(2):377-378. doi:10.2466/pr0.1993.72.2.377

  3. Roese NJ, Vohs KD. Hindsight bias. Perspect Psychol Sci. 2012;7(5):411-426. doi:10.1177/1745691612454303

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By Kendra Cherry
Kendra Cherry, MS, is the author of the "Everything Psychology Book (2nd Edition)" and has written thousands of articles on diverse psychology topics. Kendra holds a Master of Science degree in education from Boise State University with a primary research interest in educational psychology and a Bachelor of Science in psychology from Idaho State University with additional coursework in substance use and case management.