Sam Lipsyte chortlingly revels in the warty and the ruined of America, the wounded strivers who live in the world of spit, shit and piss. He's also an unrepentant self-amuser prone to the literary equivalent of fart jokes. "I bought an energy bar, and as I ate it a great weariness came over me," he wrote in his novel The Ask. But in that novel about two men who'd failed themselves in unexpected ways, Lipsyte also managed, amid gin-gimlet wit, to allow the pathos of his characters to sneak through.

In The Fun Parts (Farrar, Straus and Giroux, 240 pages, $24), Lipsyte's new short-story collection, he instead sprints along the surface of his characters like a cartoon duck over a lake, troubling the skin but leaving the depths undisturbed. "The Wisdom of the Doulas," about a male "doulo," seems designed mostly as a treatment for the first half of a lesser Seth Rogen screwball comedy about stupid men behaving badly, plus possibly traumatizing babies. In its desperation to be funny, it is desperately unfunny. It's just in a couple stories—"The Climber Room" and parts of "The Republic of Empathy"—that we spend time in the rooms where humans actually live. The best humor resides there; heck, the best dick joke in the book resides there. But for most of the collection, self-amusement comes perilously close to self-abuse.

Sam Lipsyte appears Wednesday, March 13,
at Powell’s City of Books, 1
005 W Burnside St. 7:30 pm. Free.