Heart of the matter: Jodi Picoult on the real-life drama that inspired her new novel

Should a condemned murderer try to expiate his sin by volunteering to donate a vital organ to his victim's sister?

The Mom Thing: Picoult's family are 'so not like the characters in my books' © Tom Craig

After a chilly photo-shoot under a blossoming cherry outside her Sloane Square hotel, Jodi Picoult suddenly begins lampooning American interviewers. "Year after year they ask questions like, where do you get your ideas from? – to which the best answer has to be: they arrive every Thursday morning, wrapped up neatly in brown paper."

Determined not to make that mistake at least, I take a deep breath and pitch in with a really easy question for starters. So – what is the purpose of religion?

"Far be it from me to tell you what the purpose is," she ripostes without missing a beat, "but I'd preface any answer by telling you I'm not a theologian. I learn what I need to write my fiction. Religion is something that is meant to bring people together, to make people understand what the meaning of life is, and to bring comfort."

This is Picoult in a nutshell: brisk and confident, delivering three succinct bullets on a contentious and personal matter with the implicit disclaimer that – whatever her own opinion – this statement is up for dispute rather than written in stone. Later in the interview, she promises: "If I ever get preachy, any of my fans has the right to hit me over the head with a two-by-four. The whole point of writing is to get people talking."

I pinched my opening question from a principal character in her compelling new novel, Change of Heart, in which a vagabond labourer, Shay Bourne, is convicted of murdering a seven-year-old girl and her policeman step-father. Shay becomes New Hampshire's first death-row inmate for two generations. He further inflames public sentiment by insisting that he donate his heart to the girl's critically ill sister who is awaiting a transplant, thereby enabling some expiatory good to come out of his execution. An idealistic local lawyer, Maggie Bloom, seizes Shay's request as a chance to discredit capital punishment, but her opportunistic case rests on proving organ donation to be a fundamental tenet of Shay's personal religion.

Messianic and miraculous themes carefully woven by Picoult into the fabric of her novel give the stark ethical conflicts a greater richness and complexity, but it was the individual response to spirituality that initially struck a chord. "I believe in God, but do I believe in religion? No," she explains. "The minute you organise into a religion, you're saying that if you aren't part of this group, then you are on the outskirts. And I don't buy into that. Organised religion has become a force that splits, rather than one that joins together. At the moment there's a real undercurrent in American society that says if you don't do it my way you're wrong." That "suffocating narrow-mindedness", which has flourished with the rise of the Christian right and the Evangelical Movement, gave Picoult the impetus to examine religious identity.

Picoult's worldwide fans have developed a thirst for the strong characters and contentious moral issues that collide in her tautly written ethical thrillers. Domestic abuse, teenage suicide pacts, rape and euthanasia all jostle for space in an emotionally exhausting backlist of 15 novels written in as many years. "People assume that I start to write a book by looking at the papers to figure out what the next hot issue will be," she laughs. "It's never actually like that. It's got to be a question that affects me personally, that I find myself thinking about at night, or wondering: what would I do in that situation?"

Research for an earlier book that focused on eugenics uncovered a news report that nagged at Picoult in just this manner, eventually becoming the genesis of My Sister's Keeper, the novel that brought her instantaneous success in Britain after being a Richard and Judy book club choice. The novel, in which a teenage girl sues the parents who had conceived her as a donor sibling to service her sister's leukaemia, pitches into the stormy debate over stem cell research, but its medical context tapped into more personal reserves. Years earlier, Picoult's son Jake had undergone 11 operations to address an exceptionally rare condition. She glosses over any traumatic memories, but acknowledges their percolating effect. "With something like that, I won't write about it while it's happening, because I'm too close to it; but years afterwards I'm able to let some of my own experiences bleed through into the fiction. It was only when I started writing My Sister's Keeper that that whole experience of having a chronically ill child from my own life began to inform the writing."

Jake happily survived his hospitalisation but mostly the family stay out of Picoult's fiction. Her husband, a part-time antiques dealer whom she met when she was studying creative writing at Princeton, marshals their three teenagers while Picoult is off on three-month book tours or researching new, incendiary topics. She relishes meeting fans but doesn't feel forced to write continuously while promoting. ("Frankly," she admits, "if I have clean underwear by the end of the week, that's a good accomplishment.") At home – an 11-acre corner of rural New Hampshire – she does an eight-hour day plus "the Mom thing" after school. "I get to leave my hideous, cramped, messy office in the attic every day, and I come downstairs ... they are all there and they are so not like the characters in my books. They're my safety net."

All three of her children have experienced some form of bullying, although Picoult scrupulously avoided replicating the specifics in Nineteen Seconds, her hard-hitting recent novel that anatomises a community devastated by a high-school massacre. But despite favourable comparisons with We Need to Talk About Kevin, Lionel Shriver's epistolary exploration of the same gruesome subject, Picoult still finds reviews that treat the literary merits of her own enviably popular work surprisingly elusive.

"America has a ridiculously divisive line between literary and commercial fiction," she declares, with irritation. "One New York Times reviewer skewers me annually, but the best revenge is that review coming out the same week that you have two books at number one on the bestseller lists. I'll get slagged by critics in the UK, too," she adds, "but I defy them to be able to say it's not a well-written book."

I've often found her critical reception puzzling. Picoult's formula of an ethical conundrum and taut emotional pitch is the stuff of generic page-turners, but her vivid characters have a depth and tenacity rarely found in blockbusters. Strong narrative control, a lack of sentimentality and robust but undogmatic research mark her out – as does her proven ability, evidenced by book clubs and fan-mail, to get readers discussing difficult political and moral issues, traditionally, as she points out, the domain of literary fiction.

"Early on I had to choose whether to go towards literary or commercial fiction. Literary fiction gets you the accolades and awards but no marketing budget, a small print run, and no one can find your books in a bookstore. Commercial fiction has marketing, advertising, larger print runs, and you are reaching people which, ultimately, was what I wanted to do. If I happened to slip them a well-written book at the same time then, so be it."

It's been a long haul from her 1992 debut novel's print run of 3,000 to the million-copy first American edition of her latest. Editing and teaching jobs and a Masters in Education from Harvard gave way to full-time writing as sales steadily climbed, greatly assisted by Picoult's penchant for cracking open prickly subjects that appealed to America's growing book-club readership. With a modesty that belies her exuberant confidence, she's very aware of the opportunities brought by this level of success. "When you're a novelist who is selling well, I do think that gives you a very interesting ability to have a platform," she comments. "So what do you do with it?"

With Nineteen Minutes, she used it unashamedly as a campaigning tool. "There are a hundred school districts now using the book as curriculum. Having done the research and been all over the world talking to school groups about this, the way that we're going to change things and see a reduction in school violence is by involving kids in the discussion. Having it taught in schools is a really great start. And I'm really proud of that."

The extract

Change of Heart, By Jodi Picoult (Hodder £16.99)

'... So don't judge me, unless you've fallen asleep on a couch with your ill child, thinking this night might be her last.

Ask instead: would you do it?

Would you give up your vengeance against someone you hate if it meant saving someone you love?'