By Amy Herrick

Viking. 308 pp. $24.95 Pinky, a nice wife in Brooklyn, yearns for more kids. Arthur, her taciturn husband, wants to call it a day with their only child, Teddy, a lonesome little guy who imagines the worst at all times. Arthur, that dad, is involved with a series of genetic experiments and bioengineering. Down at his lab, a lot of extremely chipper mice hang out in their cages after hours and sing.

Arthur's doleful co-worker, Marina, asks him for a sperm donation so she can have a child. (She's from a war-ravaged Eastern European country; her parents were massacred, she was heavily scarred, and she's come to America to start anew.) Marina has a little something extra up her sleeve and rummages around in the lab fridge where they keep whatever it is that's been making those mice so exuberant.

Poor Arthur, though he denies his own wife a second child, doesn't have any trouble saying yes to Marina. Then, a few months after the birth, Marina conveniently dies, leaving behind a magnificently perky baby, Bernard, who -- mysteriously enough -- seems to carry a gene for happiness. Marina's sister sends the babe over to the humble Brooklyn dwelling where Arthur, Pinky and Teddy make their home. A few mad scientists promptly go crazy with rage, greed, envy, hubris, frustration, trying to get back their most brilliant experiment.

This world in Brooklyn could have the original Mary Poppins working as a nanny down the street. Birds here pay close attention to human doings; cats live adventurous lives as full, enfranchised citizens; roses do everything but roll over and beg. The whole universe yammers incessantly with sentient meaning. Poor glum Arthur is tuned out of all this; optimistic Pinky twists like a contortionist at the Cirque du Soleil to endow the intransigent universe with patterned harmony and hope. She's a cornucopia of ethnic stories about how her folks met each other, fell in love, had children and so on. (Her most startling tale: how Teddy wouldn't even be alive if the spouses of his great-grandparents hadn't died in the Spanish influenza epidemic.) Pinky is also a barrel of laughs about how she had to play chess with her crabby husband for six months, and finally win one game, before he would allow her to conceive a child. (If I were Teddy, I'm not sure I'd think these tales were so charming. In fact, in anything resembling "real" life, I think I'd cross the street to avoid talking to either half of this couple.)

The aim of this novel is cheerful human improvement. Pinky and Arthur each have single friends who, by the end of this narrative, will probably end up spending their lives together. And there's a couple next door, drowning in isolation and accumulated misfortune who desperately need the friendship of their new good neighbors. And of course, here in the attractive backyards and quaint alleys of Brooklyn is cute little baby Bernard, who carries the happiness gene and may redeem all of future mankind.

The author has her own ideas about what constitutes that elusive state of being that we in America all have at least the theoretical right to pursue. According to Herrick, happiness means, first of all, freedom from physical pain. Dubious, lowdown characters spend much of their time here torturing the tot with lighted cigarettes, all to no avail, because Bernard doesn't feel anything. He also won't learn to talk, which implies that Herrick feels that our ability to agonize is directly connected to our verbalization skills. And Bernard heedlessly courts death, because he has absolutely no anxiety or fear. There's a downside, perhaps, to this much-advertised "happiness."

On the other hand, what if happiness consists of throwing a barbecue in your modest backyard, folding paper napkins into origami shapes, going for a run with your best friend, opening your eyes to all the gabbling birds and flowers and insects that clamor for our respectful attention?

I have mixed feelings about this novel. Its intentions are so plainly kind and good, but Pinky is such a ditz and Arthur such a pill that it's hard to care whether they end up "happy" or not. And those singles could do the world a favor, never hook up and refrain from reproducing. It could all go back to those infernal singing mice. Too much of that kind of happiness tends to provoke a perhaps churlish backlash.