Survivor Bias

You only see the winners. That’s the problem.

You see Bill Gates, Mark Zuckerberg, Steve Jobs. All dropped out of university, all became billionaires. So you conclude that dropping out leads to success. You don’t see the thousands who dropped out and failed.

That’s survivor bias. You’re only seeing the survivors, only seeing the winners, and not everybody else.

What Survivor Bias Actually Is

Survivor bias is a logical error where you focus on the people or things that survived some process whilst overlooking those that didn’t. You draw conclusions based on an incomplete data set, because the failures are invisible.

It affects every decision you make. What career to pursue. What strategies to follow. What risks to take. You look at successful people, copy what they did, and expect similar results. But you’re missing half the picture: the vast majority of people who did exactly the same thing and failed.

You can’t learn from what you can’t see, and survivor bias makes failure invisible.

The Famous Example From World War Two

Abraham Wald was a statistician during World War Two. The military came to him with a problem. Planes were getting shot down. They wanted to add armour, but armour’s heavy and slows planes down. Where should they reinforce?

They showed him data. Planes returning from missions had bullet holes clustered in certain areas. Fuselage, wings, tail. Obvious solution? Reinforce those areas.

Wald said no. Reinforce everywhere else.

The military thought he was mad. These are the areas getting hit. So why reinforce the areas without bullet holes?

Wald’s insight was simple. These planes returned. The bullet holes you see are in non-critical areas. The planes that got hit in critical areas didn’t come back. You’re not seeing them. You’re only seeing the survivors.

Reinforce the areas without bullet holes, because that’s where the fatal hits are. That’s survivor bias in action.

The University Dropout Myth

Let’s go back to the university dropout success stories.

Bill Gates dropped out of Harvard. Mark Zuckerberg dropped out of Harvard. Steve Jobs dropped out of Reed College. All of them became wildly successful, so should you drop out too?

Probably not.

Here’s what you don’t see. For the thousands of people who dropped out and didn’t found the next Microsoft, the wider statistics are fairly clear. In both the UK and the US, university graduates earn significantly more, on average, than non-graduates over their working lives. Most new businesses, of any kind, don’t make it past their first decade. Unfortunately, most dropouts don’t become billionaires. They become statistics.

But you don’t hear about them. Nobody writes books about their failures. Nobody studies their methods. They’re invisible, and that’s survivor bias.

Even a search engine has survivor bias. Search for “people who failed in business” and most of what comes back is a list of people who eventually succeeded. The actual failures? Much harder to find.

The Stock Market Example

Look at stock market graphs with beautiful upward trajectories. Markets always go up, right? Invest long-term, you’ll always be in profit?

Except that’s not the full picture. Those graphs only show surviving companies. The ones still listed. The ones that didn’t go bankrupt. The companies that failed, that got delisted, that ceased to exist, aren’t on the graph. They’re not in the index.

So the market looks more reliable than it actually is, because you’re only seeing the winners and survivors, and the losers have been quietly removed from the data.

Success Books and Self-Help

Most self-help books suffer from severe survivor bias. They study successful people, identify common traits, then tell you to adopt those traits for guaranteed success.

Some of the biggest business bestsellers of the last few decades were built exactly this way: pick a handful of companies that were doing well at the time of writing, extract the common traits, sell the formula. Several of the companies held up as the model in one of the most famous examples of this went on to run into serious trouble not long after the book was published. That’s not a criticism of any individual author. It’s the risk built into the method itself: you can only study the survivors, because the failures didn’t leave a case study behind.

Wake up at 5am. Take cold showers. Practise gratitude. Meditate. Journal. Follow these habits and you’ll succeed.

Except it doesn’t always work that way.

For every person who cold-showered their way to success, there are probably plenty who just got cold and stayed exactly where they were. Shivering, wet, and wondering why their productivity hasn’t budged and there’s no increase in their bank balance.

You don’t hear about them. They don’t write books. Nobody wants to read “How I Woke Up at 5am For Three Years and Still Live in My Mum’s Basement.”

The traits you see in successful people might be correlated with success. Or they might just be traits successful people happen to have. Causation versus correlation. Without seeing the failures, you can’t tell the difference.

The Right Place Right Time Factor

Success isn’t just about following the right formula. Sometimes it’s about being in the right place at the right time, with the right skills and the right mindset to take on an opportunity.

Gates and Zuckerberg didn’t just drop out. They dropped out of Harvard at specific moments in history, when their specific skills were suddenly incredibly valuable, and with access to resources most people don’t have. You can’t replicate timing, and you can’t recreate the unique circumstances that made their success possible then, in today’s world.

Sometimes success is luck. Sometimes it’s attrition. Sometimes it’s learning from others who failed before you make the same mistake too. Sometimes it’s just being one of the few still standing when everyone else has given up.

But you only see the end result, the survivor, not the context, and not the invisible failures.

The Bear and the Running Shoes

Two men were walking in the woods. A large, angry bear appeared. One man opened his backpack and pulled out running shoes. Started putting them on.

The second man said, “What are you doing? Those running shoes won’t help. You can’t outrun a bear.”

“I don’t need to outrun the bear,” said the first man. “I just need to outrun you.”

Sometimes success isn’t about being the best. It’s about being marginally better than the competition, or just being the last one standing.

You might succeed not because you did everything right, but because everyone else did something wrong, or someone else gave up, or you just got a lucky break. That’s not a formula you can replicate.

What You Should Actually Learn

So if you can’t just copy successful people, what should you do?

First, study failure, not just success. Learn what doesn’t work, what kills businesses, what makes projects fail, and what causes people to quit. That’s more useful than studying success because it’s more reliable. Failure has patterns, and success is often luck disguised as strategy.

Second, recognise your own survivor bias. When you look at successful people in your field, remember you’re not seeing everyone who tried and failed. You’re seeing the tiny percentage who made it. Their methods might have worked for them. That doesn’t mean they’ll work for you.

Third, be sceptical of success formulas. If someone tells you that doing X guarantees success, ask yourself how many people did X and failed. If you can’t answer that question, you’re looking at survivor bias.

Fourth, focus on avoiding failure rather than replicating success. Charlie Munger, Warren Buffett’s long-time business partner, built much of his approach on this idea: rather than trying to predict what will work, figure out what won’t work and avoid it. Invert the problem.

The Luck Factor

Luck plays a bigger role in success than most people admit, and that’s uncomfortable to acknowledge, because we want to believe success is earned, deserved, replicable.

But sometimes people succeed because they got lucky: right place, right time, right connections, right market conditions, working in the right industry for the right company.

That doesn’t mean you should rely on luck. It means you should recognise when success stories include luck, and not assume you can replicate their outcomes by replicating their actions.

Some lucky people think their success is down to skill rather than luck. All you need to do is watch their subsequent ventures fail, because their luck ran out and they never had the skills to replicate what circumstance had handed them the first time.

Perhaps the answer is to look at process rather than luck, and perhaps one day you’ll find the conditions and circumstances that help you prosper.

You can’t control luck. You can avoid unlucky decisions. I’d say that’s the better strategy.

What This Means For You

I hope reading this helps you spot a few of these biases in your own thinking, and helps you make decisions with a clearer head. But I want to be honest with you: nothing here, or anywhere else on this site, guarantees success. That’s still down to you.

Nothing guarantees success. That’s the uncomfortable truth. What you can do is increase your odds. Avoid obvious mistakes. Learn from other people’s failures. Work consistently, build skills and knowledge, and stay in the game long enough for luck to have a chance to find you.

But don’t assume that following someone else’s formula will get you their results. I will tell you now, you’re not seeing their full story.

You’re only seeing the survivor.

The Final Word

Survivor bias makes success look more achievable and more replicable than it actually is. You see the winners. You study their methods. You copy their habits. Then you’re shocked when you don’t get their results.

Perhaps it isn’t the cold showers. It wasn’t the 5am wake-ups. It wasn’t the specific morning routine. Perhaps it’s down to these people getting up and doing something each day that counts, cold shower or not. Beware of correlation, not causation.

Success is complicated. It’s part skill, part effort, part strategy, part timing, part luck. You can control some of those factors, but not all of them.

So learn from success, sure, but learn more from failure, because failure’s more honest, it happens more often, and failure shows you what actually matters.

Remember, the people telling you how to succeed are survivors. You’re not seeing everyone who did the same thing and failed.

Stay sceptical and stay realistic, and for the love of god, stay warm. Sorry, Wim, the cold showers probably aren’t working for everyone.

Further reading

• Wald, A. (1943). A Method of Estimating Plane Vulnerability Based on Damage of Survivors. Statistical Research Group, Columbia University.
• Taleb, N. N. (2005). Fooled by Randomness: The Hidden Role of Chance in Life and in the Markets. Random House.
• Rosenzweig, P. (2007). The Halo Effect: And the Eight Other Business Delusions That Deceive Managers. Free Press.
• Frank, R. H. (2016). Success and Luck: Good Fortune and the Myth of Meritocracy. Princeton University Press.
• Mauboussin, M. J. (2012). The Success Equation: Untangling Skill and Luck in Business, Sports, and Investing. Harvard Business Review Press.