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.
Take marriage, for example. In the Western world, divorce rates are higher than 40 percent: Two out of five marriages end in divorce. But newlyweds estimate their own likelihood of divorce at zero. Even divorce lawyers, who should know better, hugely underestimate their own likelihood of divorce. Although the sunniest optimists are just as likely to divorce as the next person, they are also more likely to remarry. In the words of the 18th-century English author Samuel Johnson, “Remarriage is the triumph of hope over experience.”
Many of us who have children believe that our kids will be especially talented, even while thinking our neighbor’s kids aren’t all that promising. A survey conducted in 2007 on behalf of the BBC found that 93 percent of respondents were optimistic about the future of their own family, while only 17 percent were optimistic about the future of other families. Collectively, we can grow pessimistic — about the future of our fellow citizens, about the direction of our country, about the ability of our leaders to improve education and reduce crime — while we continue to think our own future is bright.
Why does optimism about our personal future remain incredibly resilient? It is not that we think things will magically turn out okay for us, but rather that we believe we have the unique abilities to make it so.
The rosy future
Optimism starts with what may be the most extraordinary of human talents: mental time travel, the ability to move back and forth through time and space in one’s mind. To think positively about our prospects, it helps to be able to imagine ourselves in the future. Our capacity to envision a different time and place 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 mental time travel has clear survival advantages, conscious foresight came to humans 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.
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.