Hindsight Bias

When something goes wrong, we can be prone to hindsight bias, which leads us to think that something could have been predicted beforehand.

It’s that ‘I told you so’ reaction from another person who gathers evidence to try and show you how, for example, a mistake or an untoward event could have been avoided. The trouble is that this evidence is seldom conclusive and is often prone to confirmation bias — by choosing the evidence you want to prove that the event could have been predicted in the first place.

Hindsight bias is your brain’s tendency to look back at events and convince itself they were inevitable, predictable, and obvious. Once you know how something turned out, you can’t unknow it, and that knowledge floods backwards through your memory, making the past look far more foreseeable than it actually was. Research shows this effect is almost universal. Once people know an outcome, they consistently overestimate how predictable it was beforehand (Fischhoff, 1975). It doesn’t feel like a bias. It feels like wisdom.

Hindsight bias affects me at home and at work. My wife will tell me any random event of misfortune is one, well and truly, my fault, and two, could have easily been predicted if I weren’t so bone-headed or bothered to listen. It may be she is right — maybe I’ll have to accept one day she is always right — however, there are just a few times that I’m sure I can rely on hindsight bias in my defence too.

At work, in a world where it can feel like everything is someone else’s fault, my notes need to reflect the information I had at the time, not the story that only makes sense in hindsight. That’s why I document the negatives as carefully as the positives. When I examine a patient and find nothing alarming, I write down what isn’t there — not just their symptoms, but the absence of the findings that would have worried me. I do this because I know that a medico-legal lawyer sifting through clinical notes months later will be reading with the knowledge of what happened next. That knowledge changes everything. Studies confirm that knowing a case outcome significantly distorts judgments about what should have been done (Arkes et al., 1988). It’s straightforwardly good clinical practice to record the reasoning, not just the conclusion — and it also happens to protect me against the effect of hindsight bias if things are later questioned.

I know things go wrong, and I know that a small but real proportion of people who consult a doctor with what is thought to be a mild illness go on to deteriorate. These are the times when nothing short of a crystal ball could have foreseen their future deterioration. However, I still do my best to diagnose, to advise, to signpost, and to safety-net patients with good advice, but when things go wrong, and inevitably sometimes they do in the human body, some people in today’s world want to point their finger at someone.

The Blame Game

Hindsight bias is a tool people use to blame others or to blame themselves. If you suffer from it, you can probably always find something that could have predicted an untoward event, and maybe you could have stopped it from happening. The mental process is that you start thinking about the what-ifs: if I’d only been there a few minutes earlier, if I hadn’t had that last cup of tea, if I’d only rung them the week before, if I had only done this or that — or another totally non-causal thing — and then this wouldn’t have happened to them.

Here’s the crucial distinction that hindsight bias destroys. There’s a difference between a bad decision and a bad outcome. A good decision can still produce a bad outcome. A bad decision can still produce a good outcome. What separates thoughtful people from reckless ones isn’t the quality of their results. It’s the quality of their reasoning at the time of the decision. Annie Duke, in Thinking in Bets, calls the confusion of the two ‘resulting’ — judging a decision by its outcome rather than by what was reasonable to do with the information available at the time. Hindsight bias collapses this distinction entirely. It judges your past self by standards your past self couldn’t possibly have met.

Think about the last time something went wrong. A relationship that ended badly, a job you left or lost, a financial decision that didn’t pan out. Now think honestly about what you told yourself afterwards. Did you replay the warning signs you should have spotted? Did you torture yourself with the moments you could have changed course? Did you decide, with the full clarity of knowing how things turned out, that you should have seen it coming?

That’s hindsight bias at work. And it’s not just uncomfortable. It’s paralysing.

Some people blame themselves for everything that happens, whilst others try to blame someone else. But remember, blame is not responsibility; taking responsibility is about taking responsibility for your own decisions, not always about who should be blamed if things go wrong.

Hindsight Bias Can Be Weaponised Against You

People use hindsight bias as a weapon. You probably know someone who plants their flag before every major decision you make. They’ll tell you all the ways it could go wrong. They’ll lay out worst-case scenarios with elaborate detail. This isn’t concern. This is strategic hindsight. They’re not trying to help you. They’re building their case for when things do go wrong, positioning themselves to say those four words with maximum impact: ‘I told you so’. Their certainty was manufactured in advance. Their prediction is only useful to them afterwards.

Then there are others who tell you: ‘If you don’t give me X, and Y happens, it’s all your fault.’

Believe me, people can manufacture situations and worst-case scenarios in the future to manipulate or spite you, too; it’s like their hindsight bias working forward, not backwards.

There are people out there who want you to fail; not only will they tell you that beforehand, but they’ll also remind you of what they told you in the future.

The Antidote

The antidote isn’t to stop analysing the past. It’s to analyse it fairly. When you review a decision you made, you need to strip away what you know now and ask what you knew then. What information did you have? What were the reasonable options? What would most thoughtful people have done in the same position? If the answers are reasonable, you made a reasonable decision. The outcome doesn’t change that.

Confirmation bias makes this hard because your brain will naturally cherry-pick the data points that, in retrospect, seem to predict the outcome. It ignores all the data points that suggested something different might happen. You see the warning sign you missed. You don’t see the ten indicators that all pointed in a different direction. That selective memory is what makes hindsight feel so convincing, and why it’s so important to push back on it deliberately.

You’ve probably paid a higher price for hindsight bias than you realise. Decisions you didn’t make because you were still processing the last one. Risks you didn’t take because your past self looked irresponsible through the lens of retrospect. Opportunities that passed while you were busy building a case against yourself. The only real failure is refusing to try again. Everything else is just data.

Don’t let hindsight drag you back into a life you’re trying to leave behind. Your past self made the best decisions they could with the information they had. That’s all any of us can do. And frankly, it’s enough.

Keep Trying

Hindsight is great, but it only lets you fail once; it tends to stop you from trying again, especially if you didn’t succeed the first time or something went wrong along the way. You’ve got to remember that not everything works out the first time you try it, and no result is ever really perfect either.

Hindsight doesn’t always mean you were wrong; it’s just that in life, things do go wrong, and what went wrong may never have been predicted in the first place. The trouble is that life is never just plain sailing; there are ups and downs, and bad things happen to good people. Hindsight bias can really weigh you down, whack away at your self-confidence, and often be the source of the blame and guilt people carry around.

You’ve come a long way already. Don’t let hindsight bias drag you back into a life you don’t want, and don’t let it stop you from doing what you know is right, even if things didn’t go to plan the first time.

Further reading

1. Fischhoff, B. (1975). Hindsight is not equal to foresight: The effect of outcome knowledge on judgment under uncertainty. Journal of Experimental Psychology: Human Perception and Performance, 1(3), 288–299.
2. Guilbault, R. L., Bryant, F. B., Brockway, J. H., & Posavac, E. J. (2004). A meta-analysis of research on hindsight bias. Basic and Applied Social Psychology, 26(2–3), 103–117.
3. Arkes, H. R., Faust, D., Guilmette, T. J., & Hart, K. (1988). Eliminating the hindsight bias. Journal of Applied Psychology, 73(2), 305–307.
4. Roese, N. J., & Vohs, K. D. (2012). Hindsight bias. Perspectives on Psychological Science, 7(5), 411–426.
5. Duke, A. (2018). Thinking in Bets: Making Smarter Decisions When You Don’t Have All the Facts. Portfolio.