By CHRISTINE DELL'AMORE - NATIONAL GEOGRAPHIC
Added: Sun, 18 Sep 2011 23:46:34 UTC

Outmatched but victorious, the biblical figure David slays Goliath in an artist's conception.
Illustration courtesy of Lebrecht Music and Arts Photo Li/Alamy

Believing you're better than you are may help you succeed, a new study says.

For years, psychologists have observed that people routinely overestimate their abilities, said study leader Dominic Johnson, an evolutionary biologist at the University of Edinburgh in Scotland.

Some experts have suggested that overconfidence can be a good thing, perhaps by boosting ambition, resolve, and other traits, creating self-fulfilling prophecies.

But positive self-delusion can also lead to faulty assessments, unrealistic expectations, and hazardous decisions, according to the study—making it a mystery why overconfidence remains a key human trait despite thousands of years of natural selection, which typically weeds out harmful traits over generations.

Now, new computer simulations show that a false sense of optimism, whether when deciding to go to war or investing in a new stock, can often improve your chances of winning.

"There hasn't been a good explanation for why we are overconfident, and this new model offers a kind of evolutionary logic for that," Johnson said.

"It's unlikely to be an accident—we're perhaps overconfident for a good reason."

(Explore an interactive on human evolution.)

Overconfidence Pays Off When Costs Are Low

Johnson and colleague James Fowler, of the University of California, San Diego, developed a model using evolutionary game theory to explore how individuals with different strategies perform in competition with each other.

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TAGGED: BEHAVIOR, EVOLUTION