From the studio that brought you “Cars,” “Cars 2” and “Brave,” comes “Monsters University.” Graded on that curve, the new movie is not too shabby. Compared with the triumphant “Wall-E,” “The Incredibles,” the “Toy Story” films, and “Up,” this inessential prequel needs some tutoring. It’s warm. It’s likable. It’s crisply animated. It’s an underachiever.

In a prologue, sweet, elementary-aged eyeball Mike takes a field trip to the fright factory, Monsters Inc., where all-star spooks terrify children of the human world. He leaves determined to become the greatest scarer he can be.

Leaping ahead a decade, the little green olive is a well-meaning nerd in a freshman beanie, pursuing his dream at prestigious Monsters U. Problem: Mike (voiced by Billy Crystal) is book-smart but not at all frightening. The administration thinks his potential lies in a nice, dull career designing scream storage canisters. With his claws and fangs, natural-born nightmare Sully (John Goodman) expects to coast to the top of the class. The characters connect and combust, striking up a snappish rivalry. Then the dweeb and the loafer are ejected from the elite scare-track course. They’re forced to team up with the outlandish losers of reject fraternity Oozma Kappa to win another chance through the campus Scare Games.

“Monsters University” putters along amiably but never hits the heights of Pixar’s emotionally resonant classics. Heck, it pales beside “Monsters Inc.,” one of the studio’s shallower but funnier efforts. The first two acts are slow going. Crystal’s rat-a-tat Borscht Belt delivery could handle twice the volume of punch lines.

Appropriately enough, director Dan Scanlon wants this story to convey a lesson. The early incidents establish the themes of virtuous hard work and high expectations. Helen Mirren is cool and precise as the school’s intimidating headmistress, Dean Hardscrabble, a bat-winged dragon/millipede with refined diction and exacting standards. She seems destined to become a stock killjoy antagonist, but she serves another function, just as “Ratatouille’s” severe food critic Anton Ego (“The Grim Eater”) turned out to be an ally in disguise.

The film’s best moments arrive as things look grim for the heroes (this paragraph gets a bit spoilerish). There comes a point when our story sense tells us that Mike and Sully will suddenly vault over the many setbacks they’ve encountered and score a Hail Mary victory. Surprisingly, they don’t. The big lesson of their university experience is that they have a lot more to learn. It’s a refreshing twist of a coda.

With its abundance of forgettable secondary characters and good-not-great jokes, “Monsters University” is a pleasant cartoon from a studio that once consistently amazed us. It may be time to replace the dimming bulb in the formerly brilliant Pixar desk lamp.