But on NBC’s “Who Do You Think You Are?’’ celebs with perfectly hued hair including Sarah Jessica Parker and Brooke Shields will be seeking their own genealogical roots. The new show, which premieres tonight at 8 on Channel 7, represents the reality-TV extension of the urge that Alex Haley stoked in the mid-1970s with “Roots’’ and that now flourishes on websites such as ancestry.com, genealogy.com, and myheritage.com. People remain driven to understand who they are in terms of where they came from, to feel a sense of grounded identity in this relentlessly fast-paced, present-tense, and digitized world.

Based on a popular British series with the same title, “Who Do You Think You Are?’’ is the People magazine version of PBS’s “Faces of America With Henry Louis Gates Jr.’’ Each episode is devoted to a single star, as he or she travels from expert to historian to family member for factual ancestral information. Tonight, Parker traces her family tree back and back, traveling from New Jersey, where we meet her mother, to Cincinnati to California to, finally, Boston and Salem. Turns out Parker may be related to someone involved in the Salem witch trials.

True to its reality-TV roots, “Who Do You Think You Are?’’ is presented in heavily dramatized terms. The narration is over-baked and, at times, unintentionally funny, such as when the narrator announces, “Coming up, Sarah Jessica finds out whether her ancestor was accused of being a witch.’’ The soundtrack music and montages are also manipulative and intrusive. And each discovery Parker makes is an opportunity for her to appear stunned, blown away, moved, and touched - to perform just a little bit.