Optimism Bias

You’re going to be fine.

That’s what you tell yourself, you’re less likely to get lung cancer even though you smoke. You’re less likely to have a car accident even though you text while driving. You’re less likely to fail even though you haven’t prepared, you’re going to be the exception to the rule.

That’s optimism bias talking, and it’s both keeping you alive and potentially killing you at the same time.

Optimism bias is the cognitive tendency to believe you’re less likely to experience negative events than other people around you. It’s the voice in your head that says bad things happen to other people, not to you. You’re special. You’re different. The statistics don’t apply to you.

At first glance, this sounds like a very good trait, optimism is healthy, right? It motivates you, it keeps you going through hardship. It helps you see the bright side when things get difficult.

All true, but there’s a problem.

Optimism bias isn’t just healthy optimism. It’s a false illusion of invulnerability. It makes you feel you’re less likely to get lung cancer if you smoke, more likely to survive without a helmet on your bike, safer taking needless risks. You genuinely don’t think anything bad is going to happen to you, even when you’re doing things that statistically lead to some very bad outcomes.

This bias causes really poor decision-making, and that’s where disasters happen.

Add drugs, alcohol, hormones, or a teenage brain (or all of the above) to optimism bias and you can see how problems escalate. Needless risk, and optimism bias go hand in hand.

In my experience engaging in risky behaviour is simply risky. The trouble is, it’s also addictive. Take a chance, get away with it, get a thrill, take that risk (or an even greater risk) again and again, and ride your luck reinforcing your optimism bias until disaster finally catches up with you.

I see patients who keep smoking because they think they won’t be the one who gets cancer. They know the statistics. They just don’t think those statistics apply to them. Then they get the diagnosis. Then they’re shocked. Then they tell me they never thought it would happen to them.

That’s optimism bias.

Here’s the paradox though. We need optimism bias. Take it away completely and you get into a really difficult predicament.

Clinical studies that have combined results from multiple research papers on depression show that clinical depression is associated with roughly a 50% increase in relative risk of death. The association is complex and reflects many contributing factors, including comorbid illness, smoking and lifestyle, rather than pessimism itself shortening life on its own. Even so, pessimism and lack of hope, the opposite of optimism, are key psychological and cognitive features of depression.

Losing all optimism is not good for you. Get hit by something big, lose a loved one, lose your independence, get a major illness, and you see people literally lose the will to live. They stop trying. They give up. They die earlier than they should.

So optimism is hardwired into you for a reason. It’s there so you don’t lose hope. It’s there so you can look on the bright side when things go bad. It’s there to stoically keep you going through loss and hardship, and sometimes optimism is the only reason people keep going, when things are going against them.

If you are optimistic you can see yourself achieving something in the future, so with optimism it makes the work and suffering worthwhile today.

Optimism means you look forward to the future, you plan ahead for the best, and you put up with difficult things. With optimism you pursue your goals, you stay confident even when the future seems bleak to others.

Optimism is self-fulfilling. Without it, you wouldn’t achieve anything. You wouldn’t take the first step. You wouldn’t be able to imagine a compelling future that would justify the work needed to get there.

So you need optimism. But you don’t need too much optimism bias in your thinking patterns.

There’s a difference.

Healthy optimism says things might work out if you put in the effort. Optimism bias says things will work out regardless of whether you put in the effort. Healthy optimism says you can handle challenges if they come. Optimism bias says challenges won’t come to you specifically.

Healthy optimism is realistic about risk but chooses to focus on possibility. Optimism bias is unrealistic about risk and pretends the possibility of bad outcomes doesn’t apply to you personally.

You need the first. You don’t need the second.

Here’s how optimism bias shows up in your life.

You underestimate how long a project will take, you might think you can finish it in a week even though similar projects have taken you a month in the past. That’s optimism bias. You’re not learning from history because you genuinely believe this time will be different.

You underestimate the difficulty of change, perhaps you think you’ll easily quit smoking, lose weight, start exercising, change your career. Other people struggle with these things, but you won’t, because you’re different. That’s optimism bias talking.

You underestimate the likelihood of negative events. You don’t think you’ll get sick, lose your job, have relationship problems, face financial difficulties. Those things happen to other people. Not to you. That’s optimism bias creating a false sense of security.

You take unnecessary risks because you underestimate the consequences. You drive too fast, you don’t save money, you don’t prepare for problems. Why would you? Nothing bad is going to happen to you specifically. That’s optimism bias setting you up for disaster.

The research on this is fascinating and terrifying in equal measure.

When researchers ask people to estimate their likelihood of experiencing negative life events compared to the average person, almost everyone rates themselves as less likely than average to experience divorce, job loss, illness, accidents, or financial problems. For many of these events that’s not the statistical impossibility it first appears to be — risk is often skewed, so a small high-risk minority drags the average upward and most people genuinely are below it. Which is exactly why optimism bias is so hard to catch: your sense that you’re the exception is usually right, right up until the one time it isn’t.

You see this in financial planning. People consistently underestimate how much money they’ll need for retirement, they’re optimistic about future earnings and pessimistic about future expenses. They don’t plan adequately because they genuinely believe everything will work out fine without much planning.

You see this in health behaviours. Smokers know smoking causes cancer but don’t think they’ll be the ones who get it. People who don’t exercise know it’s bad for their health but don’t think they’ll be the ones who have heart attacks. They’re optimistic that the statistics won’t apply to them personally.

You see this in entrepreneurship, new business owners are wildly optimistic about their chances of success even though the statistics on business failure are well known. They think they’re different. They’re not being irrational on purpose. They genuinely believe they’re more likely to succeed than average.

Sometimes that optimism drives them to work harder and they actually succeed. Sometimes it drives them to take unnecessary risks and fail spectacularly. The difference is whether the optimism is paired with realistic assessment of risk and proper preparation.

So how do you balance this?

You need optimism, you need to believe things can work out, you need to have hope in your life, and you need to be able to imagine a better future.

But you also need to recognise when your optimism has crossed into optimism bias.

Here’s how to tell the difference.

Healthy optimism prepares for problems while hoping for the best, whereas optimism bias assumes problems won’t happen so doesn’t prepare you.

Healthy optimism says you can handle challenges if they arise. Optimism bias says challenges won’t arise for you specifically.

Healthy optimism learns from past failures and adjusts. Optimism bias dismisses past failures as flukes and doesn’t adjust.

Healthy optimism takes calculated risks, however optimism bias takes unnecessary risks.

Ask yourself these questions.

Am I preparing for potential problems or assuming they won’t happen to me? Am I learning from my past experiences or dismissing them as not relevant to this situation? Am I taking calculated risks or unnecessary ones? Am I being optimistic about my efforts or optimistic about outcomes regardless of effort?

If you’re assuming bad things won’t happen to you personally, that’s optimism bias. If you’re believing you can handle challenges if they come, that’s healthy optimism.

If you’re not preparing because you think you won’t need to, that’s optimism bias. If you’re preparing while hoping for the best, that’s healthy optimism.

If you’re dismissing warning signs because you think you’re the exception, that’s optimism bias. If you’re noting warning signs but choosing to move forward anyway with appropriate precautions, that’s healthy optimism.

You need optimism to get through life. To take some risks. To try new things. To keep going when things get hard. Without it, you’d never leave your house. You’d never start anything new. You’d be paralysed by fear of all the things that could go wrong.

But you also need to recognise when your optimism has become unrealistic. When you’re not just hoping for the best but assuming the worst won’t happen to you. When you’re not just confident in your ability to handle problems but convinced problems won’t arise in the first place.

That’s the line. That’s where optimism becomes optimism bias.

Stay on the right side of it.

This isn’t therapy. If you’re dealing with clinical depression, severe anxiety, or trauma, please see a professional. I say this as a doctor, not as a disclaimer.

Further reading

• Weinstein, N. D. (1980). Unrealistic optimism about future life events. Journal of Personality and Social Psychology, 39(5), 806-820.
• Sharot, T. (2011). The optimism bias. Current Biology, 21(23), R941-R945.
• Taylor, S. E., & Brown, J. D. (1988). Illusion and well-being: A social psychological perspective on mental health. Psychological Bulletin, 103(2), 193-210.
• Harris, A. J., & Hahn, U. (2011). Unrealistic optimism about future life events: A cautionary note. Psychological Review, 118(1), 135-154.
• Shepperd, J. A., Klein, W. M., Waters, E. A., & Weinstein, N. D. (2013). Taking stock of unrealistic optimism. Perspectives on Psychological Science, 8(4), 395-411.