NBC's 'Who Do You Think You Are?' TV series explores 7 stars' family histories

Lisa Kudrow discovered that doing genealogy and family history can be an emotional journey.

She knew that members of her family had been murdered by the Nazis during World War II. But going to Belarus for the new NBC series "Who Do You Think You Are?" made that real.

"It's being there and walking the same path that these people walked to their death that doesn't allow you to keep it at an emotional distance like I was always comfortable with before," Kudrow said in a teleconference with TV critics.

"There's a deeper impact with it. And then also knowing that as hard as it was, knowing that the story's going to reach a lot of people. … And the intimate details of these stories give personalized history the impact it's supposed to give."

Kudrow, the former "Friends" star, is not only the subject of one of the episodes of "Who Do You Think You Are?" but one of the executive producers. She was captivated by the original British version of the show.

"I fell in love with the show," she said. "I thought it was fantastic and wanted to know why we don't get to have that in the U.S."

The seven-episode series, which premieres Friday at 7 p.m. on Ch. 5, takes seven celebrities on very personal, yet highly relatable journeys. In addition to Kudrow, episodes feature Sarah Jessica Parker, Emmitt Smith, Matthew Broderick, Brooke Shields, Susan Sarandon and Spike Lee.

But while the family histories belong to celebrities, the histories are almost entirely about the people next door.

"While the person who's taking the audience on this journey is well-known, their great-great-grandfather was not famous," Kudrow said.

"Most of their parents weren't," said executive producer Dan Bucatinsky. "I mean, we go back one parent, and they're regular folks."

But that doesn't mean dull. Parker discovers she had ancestors caught in the middle of the Salem witch trials. Smith and Lee each find both slaves and slave-owners. Broderick learns of heroes in both World War I and the Civil War.

Shields discovers Italian and French nobility on one side, working class tragedy on the other. Sarandon solves a family mystery.