The trailer, the casting, even the title of “The Guilt Trip” sets us up for a specific kind of movie: Nice neurotic boy henpecked by his nagging, smothering Yiddishe mama. It’s a dynamic we’ve seen everywhere from the novels of Philip Roth to Woody Allen’s “Oedipus Wrecks” and countless other movies and sitcoms over the last half-century or so.

But “The Guilt Trip,” starring gravelly voiced everyslacker Seth Rogen as the son and Barbra Streisand as the mom, has its own agenda that goes far beyond cheek-pinching and boiled chicken.

The movie, directed by Anne Fletcher (“The Proposal,” “27 Dresses”) from a script by Dan Fogelman (“Crazy Stupid Love,” “Cars”), may occasionally err on the side of innocuousness, but at least it explores actual facets of the mother–adult son relationship without veering into caricature.

Young inventor Andrew Brewster (Rogen), at the end of his financial rope, sets out on a cross-country road trip in an attempt to sell his organic cleaning product to one of the major retail chains. Flying to his home in New Jersey from L.A., he pays an all-too-rare visit to his mother Joyce (Streisand), who dotes on her son cross-country with a seemingly endless series of phone messages, sharing everything from encouragement to tips on underwear sales at The Gap.

During his visit, Andrew tries to get Joyce to go to a singles’ mixer for older people, but she’s clearly not having it. That night, she tells him about her first love, a boy from Florida whom she loved passionately but who ultimately never proposed to her, suggesting instead that she accept the offer from Andrew’s father.

Andrew tracks the man down on Google, finds him in San Francisco, and suggests that Joyce accompany him on the trip, mainly so he can attempt a reunion by the bay for his mom and the guy she never fully got over.

In a cheesier movie, the rest of the film would just be about overbearing Joyce getting on Andrew’s nerves in an enclosed space, but “The Guilt Trip” goes in smarter directions than that, whether it’s the two of them listening to the audiobook of Jeffrey Eugenides’ “Middlesex” (a constant source of discomfort for Andrew, who feels awkward listening to discussion of genitals in his mother’s presence) or Joyce’s attempts to help Andrew out with both his professional and romantic life.

Viewers of a certain age will be thrilled to know that Joyce’s advice is right far more often than it’s wrong. In fact, one of the film’s strengths is that both characters genuinely learn things from and about each other in ways that rarely feel contrived or phony. Mother-love tends to get a bad rap in pop culture, but not here.

There’s not a ton of plot, granted, but the real pleasure of the film comes from watching Rogen and Streisand (looking more loose and relaxed than she’s appeared in any medium for some time) interact. I will always, always laugh uproariously at “What’s Up, Doc?” no matter how many times I see it, so it’s been disappointing to see Streisand ignore her comedic roots for so long. (And let’s not count the “Fockers” movies, which did no one’s funny bone any favors.) Her unflagging insistence and his laid-back withdrawal mesh perfectly; this is a comic duo that should keep working together.

The movie’s also peppered with lots of great character actors, who apparently agreed to glorified walk-ons just for the opportunity to spend a day with an icon like Streisand: Keep an eye peeled for the likes of Kathy Najimy, Adam Scott, Casey Wilson, Rose Abdoo, Miriam Margolyes, Colin Hanks, Dale Dickey and Nora Dunn, among others. (Special mention to Brett Cullen, most recently seen in the “Red Dawn” remake, as a soft-spoken Southwesterner smitten with Joyce and her skill at putting away a big steak dinner.)

“The Guilt Trip” is too gentle to be uproarious (although no one makes a comment like “This place smells like strawberry gum” about a topless bar the way Streisand can), but if you’re in the mood for something easygoing and well-acted, it’s a sweet little character piece. Take your mom -- or at least call her. You know how she worries.