Key takeaways
- Optimism bias is the belief that good things are more likely, and bad things less likely, for you than for others.
- Neuroscientist Tali Sharot estimates that about 80% of people show it.
- It supports motivation, but it can lead people to skip precautions.
Ask a room full of people whether they are better drivers than average and most hands go up. In a 1981 study by Ola Svenson, 93% of the American students surveyed placed themselves in the top half for driving skill. Statistically, only half of them can be right.
What optimism bias is
Optimism bias, sometimes called unrealistic optimism, is the tendency to believe you are less likely than other people to experience negative events and more likely to experience positive ones. Psychologist Neil Weinstein documented it in 1980, asking students to rate their chances of events like getting divorced, having a heart attack or owning a home compared with classmates. On average, they rated themselves better off on almost everything.
Later work by Tali Sharot and colleagues suggested that the brain updates beliefs more readily after good news than bad news. If you learn your risk of something is lower than you thought, you adjust. If it is higher, you adjust less.
Why it exists
Optimism feels good, and it may help us keep going. People who expect things to work out are more likely to try, to persist and to recover from setbacks. A world where everyone expected the worst would have fewer startups, fewer marriages and fewer people training for marathons.
Where it costs you
- Money: under-saving for emergencies or retirement because “it will be fine”.
- Health: skipping screenings or ignoring symptoms.
- Time: underestimating how long projects take. This is the planning fallacy.
- Relationships: assuming a partner will change, or that a situationship will turn into more.
How to keep the upside
You do not need to become a pessimist. Keep the optimism for motivation and add one realistic habit:
- Use base rates. Before you predict your own outcome, look up how it usually goes for people like you.
- Plan for the boring risk. Insurance, a savings buffer and a backup plan cost little and protect a lot.
- Pre-mortem it. Imagine the plan failed and list three reasons why. Then fix the most likely one.
Curious where you sit? Take our Optimism Bias Test. It is modelled on the kind of comparison questions used in early research, and takes about two minutes.
Try it: Optimism Bias Test
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