The Psyche Behind Ambition: Driven or a Little Crazy?

July 3, 2007 — -- If it's got Oprah's name on it, it's got to be good.

At least that's the consensus of most Americans, who tune into her hit talk show, snatch up her magazine and click more than 68 million page views a month on her Web site. And she's charitable too: The Oprah Winfrey Leadership Academy for Girls in South Africa opened its doors in December.

It seems like everything Winfrey touches turns to gold.

And it looks like she's about to rack up quite a few more doubloons.

The newest addition to the Winfrey empire, a store in downtown Chicago located just across the street from her show's studio, is currently in the planning stages. The retail space will sell items similar to those available in her Web site boutique and will presumably add to the celebrity's popularity -- not to mention her net worth.

Similarly, Donald Trump's business acumen has landed him everything from his own reality show to lines of eponymously titled vodka, bottled water, steaks and even Trump University, a school that teaches -- you guessed it -- business management.

Celebrity entrepreneurs like Martha Stewart and Steve Jobs work just as hard to carve their niche in the marketplace.

Will these mega-ambitious moguls -- already richer than the average person could ever imagine -- ever stop expanding on their self-made brands?

According to one expert, many successful business people may have a genetically based temperament that is actually considered manic.

John Gartner, the author of "The Hypomanic Edge" and an assistant professor of medical psychology at Johns Hopkins Medical School, told ABC News that the ambitious nature of people like Winfrey and Trump could be attributed to hypomania, a condition that elevates a person's energy, creativeness and willingness to take risks.

"It's a temperament that is similar to mania but is milder, and so more functional," said Gartner. "The energy, the confidence, the risk-taking and not needing much sleep are physiological traits that people are born with, and you do see them in people like Oprah Winfrey and Donald Trump and Steve Jobs."

"A little bit of mania seems to be correlated with success and ambition," said Gartner. "These are people who are very highly motivated biologically -- their motivational sensors are firing at a very high rate."

Their bank accounts are similarly over the top.