We all like to think of ourselves as rational creatures who smartly prepare for the worst. We watch our back, weigh the odds and pack an umbrella when the skies look threatening. But although we take such precautions, we generally expect things to turn out pretty well — often better than they do. The belief that the future will be better is known as the optimism bias, and most of us have it. Tali Sharot, special to the Washington Post
For instance, people hugely underestimate their chances of losing their job or being diagnosed with cancer. They also envision themselves achieving more than their peers and overestimate their likely life span, sometimes by 20 years or more.
In short, we are often more optimistic than realistic.
In the Western world, two out of five marriages end in divorce. But newlyweds estimate their likelihood of divorce at zero. Even divorce lawyers, who should know better, hugely underestimate their own likelihood.
Although the sunniest optimists are just as likely to divorce as the next person, they are also more likely to remarry.
Mental time travel
Why does optimism about our future remain incredibly resilient?
It is not that we think things will magically turn out okay, but rather that we believe we have the unique abilities to make it so.
Optimism starts with what may be the most extraordinary of human talents: the ability to move back and forth through time and space in one's mind. Our capacity to envision a different time and place — mental time travel — is critical for our survival. It allows us to plan ahead, to save food and resources for times of scarcity, and to endure hard work in anticipation of a future reward.
While this mental time travel has survival advantages, conscious foresight came at an enormous price: the understanding that death awaits.
The knowledge that old age, sickness, decline of mental power and oblivion are somewhere around the corner can be devastating.
Inside the brain
Ajit Varki, a biologist at the University of California at San Diego, argues that the awareness of mortality on its own would have led evolution to a dead end. The despair would have interfered with our daily function, bringing the daily activities needed for survival to a stop.
The only way that conscious mental time travel could have arisen is if it emerged along with irrational optimism.
The knowledge of death had to emerge in parallel with the persistent ability to picture a bright future.
The capacity to envision that future relies partially on the hippocampus, a brain structure that is crucial to memory. People with damage to the hippocampus are unable to recollect the past; they are also unable to construct detailed images of future scenarios. The rest of us constantly voyage back and forth in time.
But the brain doesn't travel in time randomly. It tends to engage in specific types of thoughts: We consider how well our kids will do in life, how we will obtain that desired job, whether our team will win, and we look forward to an enjoyable night on the town. We also worry about losing loved ones, failing at our job or dying in a plane crash. But research shows that most of us spend less time mulling over negative outcomes than we do over positive ones. When we do contemplate defeat and heartache, we tend to focus on how these can be avoided.
The good without the bad
We asked people to estimate how likely they were to encounter 80 different negative events, including developing cancer, having Alzheimer's disease and being robbed. Regardless of the variables, they always picked the rosiest forecast possible.
Where do these irrational beliefs come from? This disconnect is related to something scientists call prediction errors, which describe the difference between what you expect and what actually happens.
When we did the brain scans looking for changes that might relate to this, we found a few brain areas, including the left inferior frontal gyrus, responded to unexpected good news. For example, when someone thought his likelihood of cancer was 50 percent and we told him it was only 30 percent, this region responded fiercely.
On the other side of the brain, the right inferior frontal gyrus responded to unexpected bad news. But it did not do a very good job. In fact, the more optimistic a person was, the less this region seemed to process bad news.
In other words, neurons seem to be able to encode desirable information that can enhance optimism, but they fail at incorporating unexpectedly undesirable information. When we hear a success story, our brains take note of the possibility that we, too, may become immensely successful. But hearing of a divorce does not make us think our own marriage could fail.
A bias that protects, inspires
Everyone shows an optimistic bias. Behavioral economist Andrew Oswald found that from about the time we are teenagers, our sense of happiness starts to decline, hitting rock bottom in our mid 40s. Then our sense of happiness miraculously starts to go up again rapidly as we grow older. And, it doesn't matter if we are happy, healthy, have money or children. Older individuals are just plain happier and more satisfied than middle-aged individuals even though their health is usually worse.
Oswald tested half a million people in 72 developing and developed nations. He observed the same pattern across all parts of the globe and across sexes.
And it's not only we humans who slump in the middle and feel sunnier toward the end. Even chimpanzees and orangutans appear to experience a similar pattern of midlife malaise, Oswald found.
Why would our brains be wired in a way that makes us prone to optimistic illusions? It is tempting to speculate that optimism was selected by evolution precisely because, on balance, positive expectations enhance the odds of survival.
The optimism bias protects and inspires us: It keeps us moving forward, rather than to the nearest high-rise ledge. To make progress, we need to be able to imagine alternative realities, and not just any old reality but a better one; and we need to believe that we can achieve it. Such faith helps motivate us to pursue our goals.
Tali Sharot is a research fellow in cognitive, perceptual and brain sciences at University College London and author of "The Optimism Bias: A Tour of the Irrationally Positive Brain." This article was excerpted from the new e-book "The Science of Optimism."