'My real life always comes first'

It may become more difficult to keep since her novel has been shortlisted for the Man Booker prize, but Zadie Smith prefers a low profile, she tells Anna Carey

Zadie Smith doesn't like doing interviews. In fact, she dislikes media attention in general, so much so that she's considering leaving England to avoid it. Although she loves her native north London, and lives across the road from the house where she grew up, Smith says she'd like to go back to the US for a year or two, maybe San Francisco, just to get away from what she sees as too much press attention.

"In England there's more stuff trying to wind me up, stuff that I don't want to read or see," she says. "And in America I don't ever read or see it. I'm talking about commentary, gossip, profiles, articles - interviews. I have to try and avoid it. I have to try and do my work, and to do that I have to pretend that my life hasn't changed."

It has changed, though, ever since her hugely successful debut, White Teeth, appeared in 2000. Smith is currently in the hated spotlight because of the publication of her third, and best, novel, On Beauty, which has just been shortlisted for the Man Booker prize. Smith was taken aback by the announcement.

"I said I had no f***ing chance of getting on the Booker shortlist because it seemed to me that the longlist was of an incredibly high standard," she says. "I am amazed and delighted to have been shortlisted alongside British and Irish writers for whom I have nothing but respect."

Less showy and more humane than her previous books, On Beauty is set in the rarified world of American academia, and tells the story of two very different families whose lives are drawn together by a brief romance. From its opening line ("One may as well begin with Jerome's e-mails to his father"), On Beauty explicitly draws from EM Forster's Howard's End, from which it borrows not just its beginning but much of its structure and the inspiration for some of its characters.

But Smith never intended to write a reworking of Forster's novel. "I was just about to start writing about two families, and the son of one family falling in love with the daughter of the other," she says. "And then my husband pointed out that this was like Howard's End. Once he'd done that, I thought I'd reference [Howard's End] directly, and it was fun. I didn't want to make it too explicit, though. Howard's End kind of drifts in and out of [On Beauty]; sometimes it's there, sometimes it's not."

What she really wanted to do was "write about a marriage that was breaking down. And I knew I wanted them to be intellectuals. I wanted to write about how intellectuals mess up their personal lives."

The marriage at the heart of the novel is between Howard Belsey, a liberal, white English academic who teaches at a small but prestigious American college, and his African-American wife Kiki. They have been married for 30 years and have three children when their relationship begins to unravel. Unlike some of her contemporaries, Smith has never shied away from writing about people of her parents' generation.

"I like to write about people of different ages," she says. "I like to write about families, and of course in families some people are going to be much older than me and some are going be younger. But I'd never want to write a novel that's just about people in their 20s, because life isn't like that."

Smith studied English at Cambridge, and loved it. "For a while it stops you reading for enjoyment, but it made me a much more effective thinker," she says. "It was what I had always wanted to do. I can't do anything else, so it wasn't really a choice, it was a matter of incompetency in every other area! I would have never got to university at all if it weren't for English literature."

But she swapped England's Cambridge for its Massachusetts version when she went to Harvard on a fellowship in 2002, shortly after the publication of her second novel. Life in the US wasn't too much of a culture shock.

"American universities are really not that different," she says. "They're much richer than English universities, that's the main difference." She says that the biggest shock was simply "how incredibly beautiful it was there", and New England's beauty directly influenced her work.

"I don't think I'd ever paid attention in my writing before to trees or landscape or weather. One of the things I really enjoyed when writing [On Beauty] was that for the first time I felt my characters were existing in a real physical place. I think it's because Boston weather is so incredibly extreme - it's either so hot you want to live outside or so cold you think you're going to die."

At Harvard she taught creative writing and a class on ethics and the novel; the latter is also the subject of her next book, which will consist of a series of essays on writers from Zora Neale Hurston to John Updike. She liked teaching, although her only previous experience was giving grinds "to rich kids who wanted to pass their A-Levels" the summer after graduating from Cambridge. "I enjoyed doing that, but they weren't perfect students. They were very spoiled and they didn't really want to work. But at Harvard, they all loved studying. They were unbelievable nerds, and it was fantastic."

She just taught undergraduates - "I really didn't want to teach anyone even approaching my own age" - and she says she preferred teaching the ethics and the novel course.

"Teaching creative writing is very difficult. Generally, we sat around not knowing what to do. I don't think I was a very good teacher. I think it was because of the way I was taught at Cambridge - being very formal, just lecturing, no conversation, getting very uptight if someone called me by my first name. By the end of my time there, though, that had all changed, and I think it was much better."

In the new novel, Howard Belsey represents that rigid and critical academic position, which is why Smith gave him a very different sort of artist as his specialist subject. "He's such a mighty vulgarian, is Rembrandt," says Smith. "He's all about bodies and flesh and he wasn't a great intellectual - he was a big thug with an enormous nose and a love of painting, and I like that about him. He was a popular artist in the best sense, and I thought that this was an artist that Howard would absolutely misunderstand."

She loved Guardian art critic Jonathan Jones's recent homage to Rembrandt's restored Girl at a Window. "He basically said that when you lessen an artist like that it's your loss, because you have decided to dismiss something and not get anything out of it," she says. "And I thought that was a revelatory insight into art criticism, that you can gain from loving something."

Last year Smith married Nick Laird, the Northern Irish poet whose first novel, Utterly Monkey, was published earlier this year. They met at Cambridge, when he was editing an anthology of poetry and prose in which her work appeared. Laird's poetry appears in On Beauty as the work of Claire Malcolm, a celebrated poet with whom Howard Belsey has an affair.

"I knew I had to show one of Claire's poems, but I cannot write poetry," she says. "So I had a choice. I could either make up a terrible poem and then the character's a joke, or I could either use someone else's poem and pay the rights, or I could just use my husband's poem. So using his poem made sense. And," she adds, "I just wanted to fill the book with beautiful things. And the poem is beautiful."

She points out that several critics have chastised her for using her husband's poetry, but none have criticised her for using her musical younger brother's raps, which stand in for the work of the novel's Leonard Bast-esque Carl, an aspiring hip-hop artist. "I found it really interesting. What's the difference? It's like, a poem is a very serious thing and you can't just take it, even if it's your own husband's poem, but a rap is automatically taken less seriously."

Smith and Laird both work from home, an arrangement which suits both of them. "It's just like living in a student house," she says. "Sometimes you work, sometimes you watch TV. I know a lot of writers who have offices, and go out to work every day, but I like being in my pyjamas, I like being at home. I like the cosiness of it, and I always have."

She doesn't work to a schedule. "There are too many things to do. You've got to do shopping, clean the house. I work when I've got my housework done, when I've seen my mum. And then, when there's four hours spare, I work. I really admire people who sit down and do 1,500 words every single day, and they'll get a lot more books written than I ever will, but my life, my real life, always comes first."

And yet, despite the unwelcome attention it brings, she does keep writing, because writing, as she says repeatedly, is "what I do. And when I write a novel I don't sit down with a great plan. I just sit down and start writing, and sooner or later I stop."