A black comedy à la Bad Santa —the kind of movie that hides its warm and squishy center inside a hardened shell of cynicism and makes them both taste pretty good—is tough to pull off. To work on both levels, such a film must have an appreciation both for unapologetic bad behavior and for the transformative power of human relationships. We must laugh in identificatory glee at the selfishness of the leading man or woman, and also care enough to believe that he or she deserves something more from life.
Bad Teacher (Columbia Pictures) directed by Jake Kasdan (whose last movie was the spotty but intermittently hilarious Walk Hard: The Dewey Cox Story), gets only the first part right. As Elizabeth Halsey, a promiscuous, gold-digging middle-school teacher, Cameron Diaz is enjoyably horrid. But we never detect the human being behind her exterior of awfulness or witness a moment of vulnerability, introspection, or regret. Elizabeth isn't, like Billy Bob Thornton's dissolute department-store Santa, a damaged but worthy person who reflexively holds the world at arms' length. She's just a pretty blonde jerk.
What kind of jerk? Elizabeth skips all faculty meetings and sloughs off her responsibilities on her fellow teachers, especially the enragingly perky Amy Squirrel (Lucy Punch). She smokes pot in her car in the school parking lot. She sneaks sips from a flask behind her desk while showing her students in-class movies for weeks at time. Elizabeth's attempt to quit teaching and marry rich is thwarted when her fiancé, realizing she cares nothing about him, dumps her; humiliated, she returns to John Adams Middle School to beg for her job.
Elizabeth has an eye on the new substitute teacher, Scott (Justin Timberlake), who comes from money and is volunteering out of the goodness of his heart. She brushes off the advances of the schlubby, sarcastic gym teacher Russell (who, by mere dint of the fact that he's played by Jason Segel, we know to be a decent guy). But Scott takes up with Elizabeth's arch-nemesis, the goody-goody Amy, which only redoubles Elizabeth's determination to land him for herself.
What's more, Elizabeth has long been obsessed with getting a breast job to make her already-slammin' body even more pneumatic, and she's willing to embark on all manner of embezzlement schemes to afford it. With Amy acting as informant to the principal (John Michael Higgins), the school administration slowly starts to crack down on Elizabeth's malfeasance, but not before she's gotten herself into some serious—and possibly legal—trouble.
From time to time, Bad Teacher gestures vaguely at the movie it could have been. Diaz slouches and snarls effectively through the early scenes. It isn't till we realize her redemption will be unsatisfying that the character starts to curdle. The role of Scott, a sexless, bow-tie-wearing nudnik, cannily exploits Justin Timberlake's inherent creepiness; a scene where he serenades his new girlfriend at a bar even allows him to sing (though the song, which Timberlake co-wrote, needed lyrics that were 20 percent funnier and sharper). Jason Segel, who deserves a role infinitely better than this one, gets in a few laugh lines in as the laconic P.E. coach.
Bad Teacher has one massive blind spot: For a movie purportedly about teaching, it seems curiously uninterested in children, focusing almost entirely on the sniping among the middle-school faculty. What do the kids in her class think of Miss Halsey? The students we see embody crudely drawn types: the smart preppie girl in pearls, the dunce whose mouth is constantly hanging open—but, with the exception of one nerdy, unpopular kid (Matthew J. Evans), they're barely given names, much less characters. Toward the end of the movie, Elizabeth helps the unpopular kid get through an embarrassing moment on a school field trip. But we don't sense any real connection or reciprocity between student and teacher: The boy exists purely to provide the Diaz character the redemption required by the plot. I don't like to begrudge fictional characters their happiness, but whatever good fortune befalls Elizabeth at the end of this movie felt deeply unearned. If you're looking for a funny comedy about a cynical, hard-partying school teacher transformed by his students into a paragon of pedagogical awesomeness, skip Bad Teacher and go rent School of Rock instead.