Hindsight Bias (Definition + Examples)

Have you ever heard someone say, “Hindsight is 20/20?” It’s a common phrase used by people who might have just gone through a breakup, made a decision that fell through, or are looking back on their careers. When they say, “hindsight is 20/20,” they mean that it’s easier to see what could have happened after it’s already happened. 

In this video, I’m going to break down this phrase. Psychologists do believe there is a hindsight bias that leads us to think that we can see things more clearly from the rearview mirror. But this bias isn’t always helpful. 

Highsight Bias

What is it?

The hindsight bias is a coin termed in the 1970s. It’s the phenomenon that events feel more predictable after they already happened. Even if the person could have had no way of knowing the event, the hindsight bias tells them they “knew it all along.”

Take a breakup. Your friend discovers that their partner has cheated on them, even though they were in a perfectly happy relationship. As they start to grieve their relationship, they tell you “I said that this would happen!” 

This is the first level of hindsight bias. It involves the distortion of our memory. You might have never heard your friend say that they were worried about their partner cheating on them. But due to their hindsight bias, they believe it was something they predicted.

The second level of hindsight bias is inevitability. Your friend tells you their partner was going to cheat on them anyway. It was going to happen whether they made the effort to change it or not. 

The third level of hindsight bias is foreseeability. Your friend tells you that they knew that this is how the relationship would end all along. Once your friend reaches this point, they have been swept up and fully carried away by hindsight bias. 


Highsight bias studies

Hindsight bias is a favorite study subject among psychologists. As I mentioned earlier in the video, studies on the hindsight bias began in the 1970s. Researchers asked participants to predict a series of weather or political events. Then, they went back to the participants after the events had already happened and asked them to recall what they predicted. In a strange twist of events, participants were more likely to have predicted the event after it happened – or at least, that’s what they told the researchers. 

A similar study was conducted in 1993. Students were asked to predict whether Clarence Thomas was going to be confirmed to the Supreme Court. A month after the confirmation, the students were asked again what they had predicted. There was a significant amount of memory distortion among the students. 

Studies show that there are patterns in where hindsight bias appears. Events like “seeing the future” and knowing about a surprise result are likely to result in hindsight bias. (An example of this is the Clarence Thomas confirmation.) When it comes to smaller, more personal events, things may vary. If the surprise event was a success, it’s more likely to be vulnerable to hindsight bias. If the surprise event was a failure, people are more likely to keep their memories intact. 

Let’s say you were entering a contest, but you knew you’d be a long-shot. Turns out, you win! You’re more likely you believe that you knew you’d win all along. If you lose, you’re more likely to be honest with your predictions. 

What causes it? 

What causes the Hindsight Bias?

Hindsight bias can play serious tricks on our minds, and even causes people to rewrite history. But why does this happen when we still have memories of our thoughts and feelings before an event? 

Psychologists are still trying to dig deep into the “why” behind hindsight bias, but one explanation says that it happens when we make sense of an event. Hindsight bias usually occurs when something surprises us. Surprisingly, your friend’s partner cheated on them. Surprisingly, a thunderstorm rolled through town. When we encounter surprise, our brain urges us to make sense of the event. 

In order to make sense of the event, the brain will have to form a story that uses factors from before the surprise to lead up to the surprise. The dog was howling before the thunderstorm. The partner stayed late at work one too many times. When we put all of this together, it can seem obvious that the surprise event happened in the first place. 

Another explanation is that we focus so much on the outcome of the event that anything leading up to the event is more vulnerable to being distorted. The memory of the breakup, or the election results, or the success is so strong that everything else is not as clear. 

Problems With Hindsight Bias 

Hindsight bias isn’t just a fun phenomenon to study – it’s important for everyone to be aware of hindsight bias and how it can affect the way you make decisions. Hindsight bias literally rewrites our memory and shapes the way we predict things in the future. If you are a student, a gambler, or just someone who benefits from a solid memory, be aware of hindsight bias.

We Write Off Information That We Should Study

Let’s talk about being a student. Hindsight bias can affect us as we read from a textbook. We look over the information that is coming up on a test and tell ourselves, “I know this already.” We take quizzes leading up to a test and tell ourselves, “I knew what was going to be on the quiz. I know this stuff!” 

This can lead us to be more confident of our skills than we really are. During the time between the quiz and the final test, we could forget the information that we will have to know. Even worse, we could walk into the test super confident based on how we remembered the quizzes. 

So study hard. Don’t let past quizzes stop you from going over material that could be on the test. 

We Forget the Odds 

We forget the odds example

Gamblers also fall prey to hindsight bias. Being cocky about your ability to predict a surprise outcome is not always good if you’re gambling. Hindsight bias leads many people to forget the odds of an event occurring, especially if the less likely event just occurred. 

Want to know more about biases in gambling? Check out my video on the gambler’s fallacy. Hindsight bias is only one example of how our brains can lead us astray. But with proper knowledge of these biases and how they affect memory, we can begin to look at events more objectively and better predict the right outcomes.

Theodore T.

Theodore is a professional psychology educator with over 10 years of experience creating educational content on the internet. PracticalPsychology started as a helpful collection of psychological articles to help other students, which has expanded to a Youtube channel with over 2,000,000 subscribers and an online website with 500+ posts.