Generosity, By Richard Powers

Can excessive happiness really be catching?

Russell Stone teaches creative writing at a two-bit Chicago college. He hails from a family of congenital depressives and is hunched with low self-esteem, but among his variously untalented students is the remarkably gifted Thassa Amzwar, a Maghrebi refugee whose brutal heritage of family loss in Algeria's vicious conflicts is fully eclipsed by her irrepressible joie de vivre. "Glowing like a blissed-out mystic", her very presence lifts the spirits of all who come into contact with her.

With honest intentions, Stone consults the college shrink about Thassa's aura, worried that she is "either on newly discovered anti-depressants or so permanently traumatised she's giddy". Candace Weld is bowled over after the briefest of encounters. Her diagnosis of possible hyperthymia – excessive happiness – leaks to the local press after an attempted rape by a fellow student. Viral blogging and web gossip about Thassa's rapist-defying contentment quickly reach Thomas Kurton, the "vaguely messianic" biomedical pioneer whose research lab is exploring the genetic underpinning of happiness. Kurton persuades Thassa to let him sample her DNA.

Powers conducts the ensuing fire sale of genetic commodification and intellectual ownership with verve and brio. But it's his characters, rather than the cresting wave of incident, that have most force. Generosity throngs with vivid personalities, from the agoraphobic student to the boyish and telegenic Kurton, or the insouciant popular science-show host who flirts with him on camera. Meanwhile, late-night calls and guarded suppers bloom into an intimacy between Stone and Weld that is thoroughly charming in its uncertainty.

The volume of information in them has unbalanced some of Powers' previous works. Gain, his fifth novel, pitted a woman with a cancerous cyst against her Illinois town's polluting chemical corporation, but partially buried her tender domestic story under a somewhat dry account of the history of soap-making. Another medical theme underpinned his 2006 novel The Echo-Maker, in which, following a crash, a truck driver is unable to recognise his own sister. His extreme neural diagnosis opens up data-heavy fault lines in the novel's meandering narrative that steadily sapped fascination with the human story.

In some ways, Powers is a Midwestern Jodi Picoult, sharing a penchant for compelling, science-inflected plots and queasy ethics, but using a heavier loam of technical detail. Unlike Picoult's emotional clarity, however, Powers favours an allusive style; one that occasionally distils into rarefied meaning but often enough adds congestive wadding to otherwise vibrant plotting. But, while it still contains a hefty amount of well-researched and engrossing scientific material, Generosity is a much tighter read than Powers' previous novels, and rattles along with purpose and conviction.

Perhaps its only continuity flaw is in Thassa's aura. "Just being around her is a mild euphoria," admits Kurton, while Stone recalls "soaking in the glow of this woman, her eerie contentment". Thassa's genetic predisposition to joy is plausible, but this contagious capacity – the glow that has some physical or pheromonal property for influencing others' moods – flies well below the scientific radar and gives a mystical edge to a plot primarily impelled by hard science.