“I would suggest — and this has since been confirmed by many studies — that persistence is the single biggest predictor of future success,” Schmidt says. “And so we would look for persistence.”

Organizational psychologist and New York Times best-selling author Adam Grant agrees with the importance of persistence in success.

“Persistence is one of the most important forces in success and happiness,” says Grant. “There’s the author whose novel was rejected half a dozen times. The artist whose cartoons were turned down over and over. And the musicians who were told ‘guitar groups are on the way out’ and they’d never make it in show business. If they had quit, Harry Potter, Disney and the Beatles wouldn’t exist.”

Just make sure it’s the right determination, says Grant: “Don’t give up on your values, but be willing to give up on your plans.”

The second attribute that predicts success is curiosity, says Schmidt.

Billionaire buddies Warren Buffett and Bill Gates say that they are both driven by their inherent curiosity. “We both certainly share a curiosity about the world,” says Buffett, the famous investor and Oracle of Omaha.

“This is a phenomenal time to be a curious person,” says Gates, who co-founded Microsoft and has an estimated net worth of $75.4 billion.

For a long time under Schmidt’s tenure as CEO, Google had a famous “20 percent rule” that allowed employees to spend one out of five work days working on a project that they believed in. (The continued efficacy of the rule has been debated.) The policy, largely driven by a combination of internal motivation and curiosity, spawned such landmark projects as Gmail, Google Maps, Google News and AdSense.

“The combination of persistence and curiosity is very good predictor of employee success in a knowledge economy,” says Schmidt.

See also:

Billionaires Warren Buffett and Bill Gates are driven by the same character trait

Billionaires Warren Buffett and Bill Gates agree on the best business book ever written

Wharton’s No. 1 professor: ‘Never give up is bad advice. Sometimes quitting is a virtue.’