Tina Fey from Saturday Night Live wrote and appears in this comedy about the alternately funny and terrifying pecking order among teenage girls. Cady Heron (Lindsay Lohan) is a 15-year-old girl who has spent most of her life in Africa, where she was home-schooled by her zoologist parents. When her family relocates to the United States, Cady finds herself attending a high school in suburban Illinois, where she gets a crash course in the various sub-strata of the student body: the jocks, the cheerleaders, the stoners, the "cool" kids, and so on. Much to her surprise, Cady finds herself embraced by a clique of rich and popular girls known to outsiders as "the Plastics," led by Regina George (Rachel McAdams), Gretchen Weiners (Lacey Chabert), and Karen Smith (Amanda Seyfried). While Cady is grateful for her new friends, it doesn't take long for her to realize how manipulative they can be, and she soon discovers she's violated an unwritten law when she goes out on a date with Aaron (Jonathan Bennett), who is charming, good looking...and Regina's former boyfriend. It isn't long before Regina and her pals are on the warpath, and Cady must face a level of vengeful behavior for which years in the jungle never prepared her. Joining Tina Fey in the supporting cast are fellow SNL players Amy Poehler, Ana Gasteyer, and Tim Meadows. The screenplay for Mean Girls was based in part on Queen Bees and Wannabes: Helping Your Daughter Survive Cliques, Gossip, Boyfriends and Other Realities of Adolescence, a book by professional youth counselor Rosalind Wiseman.