SWITCHED AT BIRTH. 9 tonight, ABC Family.

I DON'T KNOW how often kids today fantasize that their helicopter parents aren't really their parents - Chris Christie's kids would probably get a pass on that right now - but the setup for ABC Family's new "Switched at Birth" has to be a dream scenario for TV writers.

Because the notion of nature and nurture being at odds gets to the very heart of adolescence.

Still, as popular as the theme of changelings and swapped infants has always been (Mark Twain alone used it twice, in The Prince and the Pauper and Pudd'nhead Wilson), the rare real instances can be nightmares, as anyone knows who followed the case of the Twiggs, the Bucks County couple who discovered only as their 9-year-old daughter, Arlena, was dying that she wasn't their biological child, and then learned that their actual daughter was living in Florida as Kimberly Mays.

That wrenching case became a 1991 NBC miniseries, also called "Switched at Birth." But there's no way it could ever have been prettied up enough for ABC Family, whose new drama probably owes more to Twain, putting one of its switched daughters in the Southern California equivalent of a castle and the other in a neighborhood where everyone has bars on their windows and girls driving expensive cars are assumed to be looking to score drugs.

Upping the angst a little: The misplaced princess, who's being raised by a struggling single mother, is deaf, the result of a childhood case of meningitis.

And that's where things begin to get interesting.

Good thing, too, because a show that relied simply on the culture clash between retired pro athlete John Kennish (D.W. Moffatt) and his fussy wife, Kathryn (Lea Thompson), and hairdresser Regina Vasquez ("The George Lopez Show's" Constance Marie) could easily get ugly.

Regina has been raising Daphne (Katie Leclerc) - who looks more like Kathryn and the Kennishes' son Toby ("High School Musical's" Lucas Grabeel) than the brunette ("Gilmore Girls' " Vanessa Marano) they named Bay - and she's clearly been doing it on a shoestring.

In a Disney world, money's not supposed to buy happiness.

It can, however, buy better living conditions, a better education and maybe even a greater foothold in the hearing world, things John Kennish assumes his newfound daughter will jump at as fast as she does a basketball.

Instead, he gets a crash course from both Regina and Daphne in the complexities of deaf culture, one that's likely to continue as Marlee Matlin guest-stars in several episodes as a friend of Regina's.

Daphne, who speaks, signs and reads lips, sets the bar pretty high for deaf characters interacting with hearing ones. (Leclerc, who has Meniere's disease, a condition that can cause vertigo and varying degrees of hearing loss, reportedly hears more than her character.)

So Daphne's kind of a star. But what of Bay, the artistic rebel whose high-school blood-typing project got the ball rolling in the first place?

Turns out thinking you don't really belong in your family and finding out you were never meant to are not the same things.

If "Switched at Birth" were a Disney movie, that little revelation would be followed by a magical solution.

It's a series, though, and so while there's a plot point looming that's straight out of "Sister, Sister," the dilemma "Switched" poses isn't going anywhere soon.

Bell kicks into high gear

Catherine Bell, frustrated action star?

Before she was one of Lifetime's "Army Wives," Bell did a lengthy tour of duty on CBS' "JAG," and her Wikipedia bio reports she's "fond of motorcycling, skiing, snowboarding and kick-boxing."

So maybe life on the Lifetime homefront, where her long-suffering character, Denise Sherwood, only occasionally gets to display her wild side, gets a little dull.

Not tonight, though: Bell stars as an Afghanistan war veteran in "Last Man Standing" (8 p.m., Lifetime) whose wife-and-mother routine is broken first by a call from an old comrade (Mekhi Phifer), then by the kidnapping of her veterinarian husband (Anthony Michael Hall) by someone who knows way too much about her black-ops past.

And instead of hanging out by the phone worrying, she gets to work, demonstrating a proficiency with computers, firearms and the intricacies of international bank transfers that might make you wonder why they didn't send Denise Sherwood after Osama bin Laden in the first place. *

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