The most nagging flaw of “Liberal Arts,” Josh Radnor’s self-consciously precious second film, comes to full fruition in a late scene, showcasing the hilariously tart-tongued Allison Janney (who also nearly saved “Juno” from its bout of cutesiness).

Jesse (Radnor), an ill-at-ease thirty-five year-old college admissions director, has been straining to reconcile his conflicting feelings for an unusually refined, virginal college sophomore, Zibby (Elizabeth Olsen), whom he met while visiting his old professor (at a school substituting for Kenyon, Radnor’s alma mater, where the film was shot). As the relationship has intensified, he’s become scared, acutely cognizant of their age difference, and after a fight in her dorm room, he retires to the local bar. It is there that Janney, playing Jesse’s jaded former Romance Lit professor, capriciously decides to take him home for a no-strings-attached fling.

Immediately after, the professor stuns Jesse by booting him out of her house. His refusal to leave, his pleading for tenderness, only exacerbates her contempt. After calling Jesse a “pussy” for quitting cigarettes, she laments his breed of “effete, articulate man-boys,” then coldly instructs him: “Don’t be one of them: go punch one in the face.” Janney’s outburst is a blast of fresh air, as many in the audience will by that point share her desire to verbally throttle Radnor’s endlessly analytical character. But Radnor doesn’t let the scene end; he insists on getting the last would-be insightful word in. Turning sadly towards the professor as he exits her bedroom, he says, “I just had the least romantic night of my life with a romantics professor. Isn’t that ironic?”

Over and over again, Radnor has his characters explicitly underline themes that are already self-evident. At the same time, he holds back from explaining more pressing questions, such as: Why would this hardened woman ever attempt a fling with this needy a man? Why doesn’t the hyper-sensitive Jesse feel worse about cheating on Zibby? What becomes of Zibby’s impulsive decision to lose her virginity to an unworthy college student? And so on.

Radnor’s first film, last year’s “Happythankyoumoreplease,” also presented Radnor as a man-child whose life is enriched by the sudden emergence of a younger muse (in that case, a child abandoned on the subway by his foster parents). That film suffered from a few groaner analogies (says a love interest disenchanted with Radnor’s flakiness: “You’re always writing short stories so you live short stories. I’m ready for the novel.”) But overall, Radnor’s witty, easygoing depiction of young, neurotic New Yorkers, how they let down their guard and let themselves fall in love, rang true.

Here, the characters are all-neuroses, and their attempts at depth are usually corny, pat little observations that are far less clever than Radnor may assume. When Zibby gives Jesse a classical music CD, for instance, he remarks, “Who says we always have to be listening to obscure indie bands?” Yes, we get it, these characters are wonderfully unique and erudite with their love of literature and classical music; why pound the point home? (the line is even more annoying since “obscure indie bands” are all over the soundtrack).

Worse, these bookish characters aren’t particularly good writers. When Jesse and Zibby exchange snail-mail letters over several months, all they talk about is their mutual appreciation for classical music, and none too eloquently (“That Beethoven symphony is no joke, and I mirror your reaction to Mozart…whoa!”) Defending her appreciation for a “Twilight”-esque franchise, Libby says, “It’s not Tolstoy but it’s not television.” And in the most cloying scene, Zibby describes herself as “a rough draft…I know I’ll get there, but sometimes I want to rush the process.” Jesse replies, “You’re the best rough draft I ever met.” Yuck.

As in “Happythankyoumoreplease” Radnor frequently resorts to montages with syrupy pop music laid on of the lovebirds walking through the campus lawn, chattering the afternoon away, but since we don’t hear most of their conversations—and what we do hear is forced and clichéd—it’s hard to feel the passion of their budding romance. It’s clear why an insecure thirtysomething would worship this pretty, poised, wise-beyond-her-years college student, but what satisfaction does Zibby get out of it? Repeatedly, she is shown alone in her dorm room, plaintively awaiting deeper commitment from Jesse, and you wonder why she doesn’t even entertain cavorting with willing and able undergraduates; surely there’s a younger version of Jesse poking around.

Sadly, though, the only other campus characters Radnor creates are dull: a suicidal, David Foster Wallace-loving loner (John Magaro), and a twenty-something Zen drifter who meditates all day long and occasionally gives Jesse key life lessons (Zac Efron). In one scene, he tells Jesse to “just go for” Zibby and forget his qualms, but the film is too timid to take that risk, and it cops out with an obvious moral about happily accepting the aging process.

To his credit, Radnor manages a few heartfelt, low-key scenes, and his actors give the roles their all. In an otherwise dreary role, Richard Jenkins, as the retiring professor, brings much resonance to his heart-to-heart talk with Radnor, where he instructs Jesse on how to graduate beyond a nineteen year-old mindset. Olsen, refreshingly sunny after her disturbing turn as a brainwashed cult member in “Martha Marcy May Marlene,” exudes a loose, playful aura, and Radnor is his usual likeable self, even when irritating. But “Liberal Arts” suffers from just that—an overkill of likability. It shies away from its potential edginess; it’s content to remain another sentimental male fantasy in the vein of “Garden State” about a confident younger woman rescuing unhappy men from disarray.