NEW YORK -- The hilarious acorn doesn't fall far from the hilarity tree.
"I think it's genetic," Tina Fey says, explaining where her acerbic humor comes from. "My mother is really dry," and her father and older brother were huge comedy aficionados.
In middle school, she enjoyed getting laughs when she cracked a joke. So by the time she was 13, she knew she wanted to "define myself, put it out there, that I was kinda funny."
Twenty years later, Fey has defined herself as the first female head writer of NBC's "Saturday Night Live," co-anchor of the show's "Weekend Update" and an Emmy winner. Now she's putting it out there as a first-time screenwriter with "Mean Girls."
The movie stars Lindsay Lohan ("Freaky Friday" and "Confessions of a Teenage Drama Queen") as Cady, a naive girl who falls in with her new high school's coolest, prettiest, most treacherous triumvirate of girls, called The Plastics. Their skills at backstabbing would make those who surrounded Julius Caesar proud. Eventually, Cady's original (uncool, outsider) friends wonder: Et tu, Cady?
Fey recognized the potential for a funny film in a New York Times article that became the best-selling book "Queen Bees & Wannabes: Helping Your Daughter Survive Cliques, Gossip, Boyfriends and Other Realities of Adolescence."
"The whole subject matter just interested me because I think some of those things that girls do to each other is sort of hilarious - even though it's painful for the girls who go through it," says Fey, who plays a math teacher in the movie.
She also finds it ingenious "that girls somehow at a certain age know how to screw with each other. ... It all rang true to me."
Not that she was a mean girl herself - or ever viciously picked on. But she recalls how girls stuck to "invisible rules" to keep each other in place.
"For example, you never say anything positive about yourself. Like you would never, ever be like, 'Hmmm, I look good today.' Because you would get smacked down so fast. And, just say, if your best friend hates some girl, you hate her too. That's part of friendship. You will help ostracize her, because your friend doesn't like her."
Mostly, Fey was "a happy-go-lucky nerd who operated in my own little social situations outside of the cool people. ... The boy-crazy part of Cady's character is certainly me, too."
She remembers liking a boy who liked another girl and she would just "obsess, obsess, obsess" about the other girl. "A lot of wasted hours just badmouthing another girl that had never really done anything to me, except be better-looking than me. That was her only crime," Fey says, laughing.
She's married now - to Jeff Richmond, who provides special musical material for "SNL" - and wanted to see if she could write a successful film "because I'm 33 and I gotta figure out if I'm gonna have a family some day (and) what kind of lifestyle can I set up for myself."
By Sunday, when the preliminary box-office figures are released, she'll find out if she gets a second chance at a screenplay, she cracks.
Lorne Michaels, the creator and longtime boss of "Saturday Night Live" and producer of "Mean Girls," thinks Fey's movie is in the tradition of those high-school-angst movies that people still fondly remember years later, such as "Fast Times at Ridgemont High," "Sixteen Candles," and "The Breakfast Club" and "Clueless" - but with a modern twist. Kids these days use 2004 technology - instant messaging, cell phones and three-way calling - to communicate and mess with each other, he notes.
Such movies have universal appeal, he says, since high school is one of the few experiences everyone has in common. "That's a tough period in people's lives. And it leaves its mark on people."
Even though the source material was a serious, nonfiction book, Michaels felt confident that Fey would find "a way into the subject matter ... She knew we were making a comedy, and also I think there was never any doubt that it would also be smart."
Growing up in the Philadelphia suburb of Upper Darby, Fey was writing school reports on comedy as early as the eighth grade. (An encyclopedia of comedy by Joe Franklin was the only reference book on the topic she could find at the time.)
Her father would encourage her to watch various comedies on TV, and her brother, who's 8 years older, was finalist when he was about 17 in a Steve Martin look-alike contest - back in Martin's arrow-through-the-head, white-suit era. Her brother also would re-enact skits from "SNL" for her, since she had to be in bed at that hour.
These days, Fey is laughing at "The Larry Sanders Show," which she's just catching up with on video because she didn't have HBO when it was on. Alexander Payne's movies ("Election," "About Schmidt") make her laugh. And her favorite comedy film of all time is the original "The In-Laws" with Peter Falk and Alan Arkin (whom she deems a genius).
She also finds it funny that she's thought of as a sex symbol.
The day before being interviewed by The Associated Press, she had professionals do her hair and makeup for a junket. "But now I'm out on my own and we can really see how ridiculous that is," she says. (Despite what sounds like genuine self-effacement, the fans who think she's a "bookish bombshell" wouldn't be disappointed on this day, either.)
She's smart enough to know, however, that such an image "can't hurt."
"All right, I'll ride this pony till I can't ride it no more," says Fey, who dropped about 30 pounds before she started appearing in front of the "SNL" cameras.
"I came from Chicago (where she, like so many "SNL" performers and writers, honed her comedy skills with the Second City comedy troupe) to New York in a very Midwestern beef-eating size. And then, as I came to New York and was a really sedentary, nervous writer my first year or two at 'Saturday Night Live,' I just bulked up a little more." Unrelated to any intention of getting on the air, she just wanted to get her weight under control.
In her seventh year at "SNL," the University of Virginia graduate is of two minds about how much longer she'll stay. "As a writer I could see ending up a lifer over there; the on-camera part ... I don't know."
She has two years left on her contract and might need a new co-anchor for "Weekend Update" come fall because Jimmy Fallon's contract is up. (Michaels hopes Fallon will stay. But after 29 years with "SNL," he says: "The one thing I've learned about the show is that change is just part of what it is.")
Fey has gotten much of the credit for the show's resurgence, though she grimaces and downplays that notion when it's brought up.
"It's very kind that someone would say that. But there's so many people that work at 'Saturday Night Live.' It would be impossible to credit me ... If people are enjoying the show more right now, I think that's great. I think it should be attributable to the cast and the writers as a whole."
No matter what happens with "Mean Girls," Fey will be busy when "SNL" returns earlier then usual next season to capitalize on the presidential election.
At the same time, Fey will continue developing a series for NBC. It'll be a comedy, and that's about all she can promise at the moment, adding: "It won't be 'Law & Order No. 8' ... 'Law & Order: Pedestrian Unit."'