In some cases, stardom seems to run in the family. From David and Shaun Cassidy, to today's successes Jessica and Ashlee Simpson, Hollywood has a long line of celebrity siblings.
Watch 20/20's full report during a two-hour special Friday at 9 pm.
Whether or not a family becomes a showbiz clan fame can take a toll on relations. Here's a glimpse at how some families handled a rise to the top.
Featured Families: Star Jones | David Cassidy | Hillary and Haylie Duff | Michael Jordan | Aaron and Nick Carter
Pop star Jessica Simpson is a virtual brand name. She has a reality show, a recording career, fast-food endorsements and a network variety show as well. And if she's a brand, the latest brand extension is her sister, 19-year-old Ashlee Simpson.
Ashlee already has a role on the WB series 7th heaven and an MTV reality show of her own on the way chronicling the production of her first CD.
"I always say that Ashlee's not following in my footsteps, she's making footsteps of her own — because she's not becoming me by any means," Jessica Simpson told 20/20.
She may be different, but their father knows that Ashlee's career has benefited from years of his efforts on Jessica's behalf. "The beauty of what's happened here, is that you don't have to knock down the doors that we've spent years knocking down to get in," said Joe Simpson.
And as the two tackle Hollywood there remains plenty of love between the sisters. According to Ashlee they "never had, like, a real fight."
"No it's, it's always stupid stuff," said Jessica. "Like if she takes all my makeup and all my clothes."
When Jessica's career began to take off, the family was strained, so they decided to move to Los Angeles to be together where she was recording her album. "With the Hollywood stories that — you know — Hollywood breaks up the family … in our case I think it saved our family," said Joe.
And the family pitched in again a few years ago, when it was time for Jessica to hit the road on tour. Ashlee had always excelled in ballet so the then 14-year-old traded in her tutu to become a backup dancer for her big sister who enjoyed having her around.
Jessica described her sister as someone who, "can have such a great personality and have everybody be in love with her, every guy lined around the corner."
"[Jessica's] so there for me," said Ashlee in response. "So there for me, and so is my parents."
Big Sis Star Jones
Viewers of a certain talk show know Star Jones as the outrageously opinionated daytime diva: Sharp, flamboyant and ready to try almost anything on television.
Her younger sister, a travel agent and mother of two, told 20/20 Star has always been a bit of a diva. "Always in the mirror," said Sheila Jones. "You know, combing the hair, putting on the makeup, the long nails, the high heels."
Like a lot of younger siblings, Sheila is happy to disclose the less flattering details of her sister, describing her also as "stuck up" and "bossy."
The two are four years apart, and while their mother liked to dress them in different colors of the same outfits, the Jones daughters could not have been more different. They are close now, but say they didn't like each other while growing up.
Star said they didn't get along because they were so different.
"Sheila, in all honesty, was everything I wished I could be," said Star. "She was outgoing. Um, very popular with the boys … Sheila had friends all over the place. And everybody adored her."