Hindsight Bias: What It Is And How To Avoid It

Hindsight bias can stop us learning from our mistakes and warp our predictions about future events.

hindsight bias

Hindsight bias can stop us learning from our mistakes and warp our predictions about future events.

Hindsight bias is the common bias for people to assume that events could only have turned out the way they did.

The hindsight bias is sometimes known as the knew-it-all-along-phenomenon or creeping determinism.

Hindsight bias can distort memories, make people overconfident and change their predictions about future events.

What is hindsight bias?

The hindsight bias is our tendency towards thinking that things must have turned out the way they actually have.

Research carried out on professionals and lay people alike has confirmed the finding.

Time and again, the outcomes of medical diagnoses, legal decisions, elections and sporting events seem more likely after the answer is known.

We display this bias across many different areas of life.

The things that happen to us seem more like they were meant to happen.

This is partly because of our drive to make sense of the world; it’s comforting to feel we can predict what is happening to us and why.

Example of hindsight bias

An example of the hindsight bias from the world of business is a good way to understand it.

Going into business for yourself is scary.

Despite all the potential rewards, compared with getting a safe job with a big firm, being an entrepreneur means accepting huge risks.

All entrepreneurs know that there are no guarantees and that new businesses fail at a frighteningly high rate.

Still many manage to convince themselves that their venture will be different.

As you might expect, as a group entrepreneurs are remarkably optimistic about their chances of succeeding (otherwise why bother?).

One study asked 705 entrepreneurs who were about to start up a new business how they estimated their chances of success (Casser & Craig, 2009).

When the researchers got back to them a while later about 40 percent had quit their new business.

This 40 percent were then asked: what did you think your chances of success were before you started?

The first time they estimated their chances of success, before their business failed, they guessed, on average, 77.3 percent.

Afterwards they recalled this figure to be 58.8 percent.

In other words the failure of their business had made them revise their original estimate downwards.

With hindsight, then, the actual outcome had become more predictable.

Factors affecting the bias

The example of entrepreneurs nicely demonstrates the hindsight bias.

Under some circumstances, the hindsight bias is particularly strong:

  1. The impression of inevitability. The hindsight bias is stronger when you can easily identify a possible cause of the event. For example, your bag was stolen because you’re a tourist.
  2. The impression of foreseeability. The hindsight bias is stronger when you are you less surprised by what happened.

Explanation of the bias

The hindsight bias occurs because we revise our estimation of an event’s probability after the fact.

When you know you team won, it seems inevitable.

People naturally look for information that confirms their view of the world — we all want to be right.

Our memories aid us in this endeavour of proving ourselves right.

The bias can make people overconfident.

How to avoid the hindsight bias

The hindsight bias can be a problem when it stops us learning from our mistakes.

If the entrepreneurs knew how biased their estimates of success were, would they have done things differently?

If trainee doctors think a diagnosis was obvious all along, how will they learn to consider alternatives?

So psychologists have looked at ways in which we can correct for the hindsight bias.

The main one is forcing people to justify their judgements and think about alternative ways in which things could have turned out.

This normally makes people see that things could easily have turned out differently.

Of course, now you know about the hindsight bias, and how it can be corrected, it seems pretty obvious, doesn’t it?


Author: Jeremy Dean

Psychologist, Jeremy Dean, PhD is the founder and author of PsyBlog. He holds a doctorate in psychology from University College London and two other advanced degrees in psychology. He has been writing about scientific research on PsyBlog since 2004. He is also the author of the book "Making Habits, Breaking Habits" (Da Capo, 2013) and several ebooks.

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