Are you an optimist? Quite likely – more than three-quarters of us are. And it’s a good thing to be: optimists are healthier and live longer. But there’s also a dark side to optimism. Optimists are not very good at being realistic, and that can cause problems.

How do you see the glass? Image credit: Sudheesh S via Flickr

Silver linings

If you’re an optimist, there are plenty of things to be glad about. Optimists are less likely to suffer heart disease or stroke and have better immunity. Optimists recover from illness more quickly, handle stress better and live longer. They are more likely to stick to dietary recommendations from their doctor and have healthier cholesterol levels. Optimists also find jobs more easily and are more successful at work. Studies of soldiers who have been held as Prisoners of War for long periods reveal that more than any other characteristic, optimism can lead to resilience in the face of trauma.

Whether you’re healthy or sick, you’re less likely to die if you’re an optimist. A study of nearly 100,000 women found the most positive women were 30% less likely to die from heart disease than women with a pessimistic outlook. Nearly 7000 U.S students entering University in the 1960s were asked to take a personality test. Researchers followed up with these students over the next 40 years. Close to 500 of them died during that period, most commonly from cancer. The pessimists had a 42% higher chance of dying than the optimists.

It’s no surprise there are plenty of people telling us life is better as an optimist. ‘Think positively’ has been a leading mantra of the self-help industry for many years.

The future looks bright

Optimism begins with mental time travel: we imagine ourselves in the future. The ability to do this has clearly been vital for human survival. Whether storing food for winter, setting off on migration or working hard now to reap rewards down the track, picturing the future is an essential skill. But it can come at a cost for optimists.

When optimists envisage the future, everything looks rosy. And to some extent that’s good: imagining a brighter future allows us to set goals. The problem comes when, in the process of thinking about a positive future, in our minds we feel like we’ve already got there. For example, obese women taking part in a weight loss program who envisaged themselves as having lost weight were less likely to actually lose weight. Those who already imagined themselves slimmer had less incentive to change their habits.

When we have happy fantasies about the future, our energy levels sag: we relax and our blood pressure drops. Sounds nice, doesn’t it. Except we end up feeling lazy and that’s the last way you want to feel when you’re trying to achieve a goal. University graduates who were doubtful and worried about whether they would get a job ended up getting more job offers and earning more than graduates who indulged in positive daydreams about their future career.

The act of dreaming about a positive future saps the motivation we need to actually achieve that future.

Rose-coloured glasses ignore risk

Optimistic thinking is widespread. Many surveys have shown just how optimistic we are about ourselves. In one study, 25% of people said they were in the top 1% for getting along with others. No less that 93% of US college students said they were above average in driving ability in another study. By definition, neither of those things can be true. We all believe ourselves to be better-than-average.

We are stubborn in our optimism: volunteers in another study were asked to imagine a variety of bad situations. Scenarios like getting fired, having their car stolen, getting divorced or developing cancer. They were asked to estimate the likelihood of this event actually happening to them. Later, the study participants were told the true probability of the misfortune occurring and then asked to reassess their own personal risk.

Let’s say someone initially predicted a 40% chance of getting cancer. When told the actual likelihood of developing cancer is only 30%, that person was quick to revise the estimate down the second time around.

How about the other way around? Someone who thinks their likelihood of a cancer diagnosis is only 10%? You’d assume when told the true risk is 30%, that person would up their estimate to reflect reality. Barely – on average, the revised estimate only goes up to 11%.

The more optimistic we are, the more we ignore negative information about the future. It’s called the optimism bias and researchers have even identified the part of our brain responsible for it. And it’s not just humans who suffer from this bias, so do rats and birds. About the only people we know who don’t have optimism bias are those suffering depression.

If most of us have it, how bad can optimism bias be? Does it mean we should all aim to be pessimists? Not at all, we just need to be aware of our bias. The problem is that being overly optimistic may stop us taking precautions to avoid harm.

So we can stay optimistic, but researchers remind us we need to be proactive: get health check-ups, save for retirement and remember to put on sunscreen. We need a heavy dose of realism with our optimism.

Hmmmm, it certainly sounds sensible but surely all will be well if I just keep assuming the best? Yep, I’m an eternal optimist.

Links and stuff

• TED talk: The optimism bias
• The Science of optimism: Wellcome Trust video
• Optimism is the enemy of action
• Book extract: the Optimism Bias