Can Melissa McCarthy make a good movie anymore?

When Melissa McCarthy, as the newly divorced, 40-something mom Deanna in “Life of the Party,” decides to re-enroll in college, my seatmate at a recent screening turned to me with a question about McCarthy’s choice of major: “What the heck is she going to do with a degree in archaeology?”

But I’m troubled by a deeper, and more existential, mystery: Why can’t McCarthy seem to make a decent movie?

Since her 2011 breakout performance in “Bridesmaids” as the loopy Megan, the actress has starred in a string of poorly reviewed duds, including “Tammy” and “The Boss” — both movies that, like this one, McCarthy co-wrote and produced with her husband, Ben Falcone. Falcone, who also directed all three, likes to give himself small, and only mildly amusing, parts in each one. Here, he’s a sensitive Uber driver who lends Deanna an ear after her caddish husband (Matt Walsh) leaves her for another woman.

There have been exceptions to McCarthy’s troubled track record. “Spy,” the 2015 film in which McCarthy portrayed a nebbishy, deskbound CIA bureaucrat who goes undercover as a field operative, was surprisingly entertaining. And yet, despite occasional flashes of comic genius over the years, as when she impersonated former White House press secretary Sean Spicer in several “Saturday Night Live” sketches, McCarthy hasn’t consistently managed to carry a major motion picture. More accurately, the movies she has chosen to make don’t live up to her considerable abilities.

As evidence, “Life of the Party” is a largely laugh-free exercise in cliche, in which we watch a middle-aged woman, clad in ugly sweatshirts and mom glasses, try to get her groove back as a student, 23 years after dropping out of school to raise a kid. Most of the comedy, which milks yuks from a tired, generational fish-out-of-water shtick, comes from seeing Deanna interact with her embarrassed daughter Maddie (Molly Gordon) and the sorority sisters at the school they all attend.

The problem is that McCarthy is, for all intents and purposes, the foil here, playing the sensible nerd to an ensemble of weirdos. Relegating McCarthy to the role of “straight man” is an odd career choice. Deanna keeps reassuring her fellow party-hearty students that she is “down to clown,” but McCarthy, it seems, never got the memo.