What's in a (Baby) Name?

Tom Cruise and Katie Holmes named their new baby Suri and Brooke Shields gave birth to daughter Grier Hammond Henchy.

Those names may seem odd, but for many celebrities, unusual baby names are a badge of distinction.

Jason Lee, star of "My Name Is Earl," named his son Pilot Inspektor. Magician Penn Gillette dubbed his daughter Moxie Crimefighter. Marlon Brando named his daughter Cheyenne, and Frank Zappa proved himself the classic hippie prankster by naming two of his children Moon Unit and Dweezil.

"A name always says a lot more about the parents than about the kid. It's a strong signal about what they want the kid to be," said Stephen Dubner, co-author of "Freakonomics."

Your Life Is Not Your Name

For example, by naming her kids Moses and Apple, Gwyneth Paltrow is indicating that they are no shrinking violets, Dubner said.

That doesn't mean, though, that Apple will behave any differently than if she were named Jane.

"Our research shows that your name has no effect on your life outcome," Dubner said.

That won't stop parents from trying unique names, though -- names that sound successful. That may mean choosing a name that sounds like it came from a wealthy family.

"Names tend to move down the socioeconomic ladder," Dubner said. "Names start out in the high end, then go to the middle, then get really popular among lower-income families."

Phoebe and Maya are top names for girls among wealthier families; Liam and Cooper, for boys. Dubner predicts those names will soon move down the ladder and become even more popular among a larger group of people.

Shields' choice of Grier didn't surprise Dubner.

"Brooke is a pretty traditional name, and she did go to Princeton," he said. "And Grier is the kind of name you'd expect from a Princeton mom."

Interestingly enough, parents don't usually name their children after celebrities, Dubner said.

"How many Madonnas and Gwyneths do you see running around the playground? As much we love celebrities, we don't name our kids after them."

Instead, they name them after movie characters, he said. The name Madison became popular after "Splash," as did Ariel after "The Little Mermaid."

So sometimes favorite movies are what's in a name.