As with Midnight in Paris (this was not a good moviegoing weekend for me), I really wanted to like Bad Teacher, if only because I agree with my friend and editor Eleanor Barkhorn that the movie’s a refreshing diversion from the idea that a saintly single educator changes everything. The movie’s jokes about substitute teacher Scott (Justin Timberlake) dry-humping Elizabeth (Cameron Diaz) on a school field trip, or Elizabeth giving a seventh-grader her bra to help him win back some cool points, aren’t as shocking as writers Gene Stupnitsky and Lee Eisenberg might have imagined they were. And the movie has a big, gooey candy center: despite smoking a lot of pot, dreaming of breast implants, giving another teacher hideous facial poison ivy, and stealing state test results, Elizabeth ends up dating the obvious nice guy in her orbit and finding her niche in giving kids advice on how to acclimate (if not more of her bras).

That said, the middle section of the movie provides a surprisingly balanced look at the question of what role performance pay and testing should play in education — along with the movie’s most successful sustained dramatic and comedic tension. When Elizabeth, who has previously gotten by showing her class Stand and Deliver and sleeping through lessons, learns that if her students get the highest scores on an Illinois State performance test, she gets a $5,700 bonus that would allow her to afford her dreamed-of breast implants, she engages as a teacher for the first time (one thing the movie does nicely is keep salaries realistic, and makes clear that $5,700 would be a game-changer for Elizabeth). Her teaching methods, including abusing her class with dodgeballs and writing the world’s meanest test comments, are unorthodox, but her students do appear to learn something. The problem is, performance pay is too much of an incentive. Worried they aren’t learning fast enough, Elizabeth dons a Little Orphan Annie wig from the school play, tells a state Education Department official she’s a reporter writing about racial biases in testing for the Chicago Tribune (“Orientals test better,” he tells her.), drugs him, and snaffles the test. Her kids ace the test, and after many hijinks, Elizabeth’s rival for the bonus check and Scott’s affections is effectively deported to a hard-case school, where her cheerful approach to teaching will presumably get her absolutely annihilated.

That realism about the uses and dangers of incentives is refreshing — performance pay is neither a panacea nor a means of destroying teachers’ pay and benefits. At one point, the school principal frets over what the teachers’ union would do to him if he demanded that Elizabeth be drug-tested with what he thinks is insufficient evidence — of course, she would be totally busted — but the union isn’t there as a malign force, either, forcing a good principal to do bad things. He’s just cowed by it, to the point of avoiding conflict that might have been worth the risk. And while the movie is clear that Elizabeth shouldn’t be teaching anyone — and by the end of the movie, she’s not — Bad Teacher does suggest that she’s good at something test scores don’t measure: helping kids acclimate to their surroundings. In this sense, the movie is kin to School of Rock, a generally warmer if less pointed movie, in arguing that obsessions with achievement, whether they come from education bureaucracies or parents, are missing the point. It’s kids’ social lives and individual growth that matter. Which means that even if one teacher isn’t the key to that growth, Bad Teacher still shares a general educational philosophy with Dangerous Minds and all the good teacher movies that have gone before it.