Richard Powers may be the nation's most predictable major literary novelist. For years, his approach has been to stitch a big idea to a much smaller story about an individual struggle, and he's never been shy about letting the seams show. "Gain" is the one about corporate behemoths and the cancer patient; "The Time of Our Singing" is the one about race and the troubled musician; "The Echo Maker" is the one about the environment and the man with the cognitive disorder. Powers is a brilliant thinker, but one who sometimes makes his characters subservient to his outsize themes.

His new novel, "Generosity: An Enhancement," sticks to the established Global Issue A Meets Personal Issue B template -- it's the one about genomics and the strangely happy woman. But if Powers novels can be measured by how human his characters remain amid the swim of ideas, it's among his finest achievements. The woman is Thassadit Amzwar, a young Algerian-born student attending art school in Chicago. Her writing teacher, Russell Stone, is a melancholy, disgraced former journalist, and he's both energized and baffled by his new student's personality. In class she relates the many horrors her family suffered in Algeria, but her good cheer remains oddly intact. "She laughs as she talks," Powers writes, "as if she hadn't just treated them all to a misery that would have broken saints."

Thassadit's classmates, equally smitten, nickname her Generosity, and her fame quickly spreads outside the classroom, catching the attention of newspapers, social networking sites and a certain mega-popular daytime TV host named Oona. Thassadit has the "happiness gene," as the media narrative puts it, and "narrative" will become an important thematic point as factions tweak Thassadit's story for their own purposes. For Russell and a school psychiatrist, Candace, she's proof of their capacity for empathy. For genomicist Thomas Kurton, she's a puzzle and potential cash cow. For TV journalist Tonia Schiff, she's the scoop of the decade. The subject of everybody's attention soon starts to crack under the strain. "I'm some kind of Jesus mascot," she tells Russell. "Or I'm going to cure their lives. Mister, it's pitiful."

Powers adds an interesting layer on top of all this: the novel's unnamed narrator, whose hidden identity speaks to other questions. Is storytelling critical to our happiness? Is a lie wrong if it lifts our spirits? Which stories should we keep to ourselves? Powers' queries would mean little if Russell and Thassadit weren't as well drawn as they are -- the big issues flow through the characters instead of drowning them. Powers has been working on that balance for decades, and when he pulls it off as well as he does here, you can't help but wish more writers were so captivatingly formulaic.

Mark Athitakis is a book reviewer based in Washington, D.C. He blogs at