[In the following interview, Smith discusses White Teeth and its reception by the public and critics.]

Zadie Smith was in the middle of her finals when she started to write the story that became White Teeth. It went on to win her a two-book deal of a rumoured quarter of a million—and she got a first. She's beautiful, too. The figure that strides into Silver Moon bookshop 15 minutes late is elegantly hip in a tight, long black skirt, warm jacket, Chris Evans specs and fur-lined hat with flaps, which she keeps on even in the cosy warmth of a nearby club. Not many people could get away with a hat like that. Not many would have the confidence to try.

The lateness, it transpires, is not to do with primadonna-ish tendencies, but the vagaries of the Jubilee Line. Zadie Smith is still living with her mother and siblings in Willesden Green, where she grew up. It was, she says, the inspiration for the novel. “If there's anything autobiographical in it,” she explains, anticipating that most familiar of first-novel questions, “then it's Willesden Green, rather than any of the people in the book.

“Yesterday I saw that woman who ignored Tony Blair [on his Tube trip to the Dome]. She lives in Willesden. One of the things I like about it is that it's a tight-knit community that doesn't look elsewhere for its standards or moral values or even aspirational things.”

White Teeth reflects the cheerful multiculturalism of the area and presents it as a microcosm of a Britain approaching the millennium. It's a huge, teeming, multi-layered brew of a book with an extremely complex plot. It centres on the friendship of Samad and Archie, Bengali waiter and English clerk respectively, who shared a secret during the war and now spend their evenings shooting the breeze in a local greasy spoon, O'Connell's.

Both married to much younger women, they produce children who embrace a variety of religious and philosophical interests, as well, at times, as each other. The multifarious strands are brought together in a plot development that hinges on a genetically engineered mouse. It is funny, clever, comes garlanded with praise by the likes of Salman Rushdie, carries a whole raft of Big Themes—racism, colonialism, fundamentalism, eugenics and genetic engineering, for a start—and is also a rollicking good read. Some achievement for any novelist, but for a 22-year-old?

“The complexity of the plot is not a strength,” observes Smith crisply. “I didn't sit down and think I'm going to write a hugely complex plot, but just to say the kind of things I wanted to say, you have to find what Eliot called the objective correlative, something that will be there, so you can make the argument you want to make. Because my argument was fairly convoluted and the themes are fairly difficult to pin down, all these things had to turn up as demonstrations of one thing or another.”

It is no surprise to hear that she had considered becoming an academic before literary success took over. Zadie Smith took the research seriously, too. She read six or seven translations of the Koran in order to write convincingly about Samad's struggles with his faith and the machinations of the militant Muslim group, Keepers of the Eternal and Victorious Islamic Nation—or KEVIN for short. She was, she says, so thrilled when she came up with the name that she “took about four days off work.”

But the point she was making about the danger of fundamentalism is very serious indeed. “This is the thing which we have to work out,” she says, rattling the ice in her now-drained orange juice. “I don't know how you deal with religions. If what Blair and the rest of them are aiming at is a multi-cultural Britain in which nobody has a faith, then I think they can forget it. I think religion's going from strength to strength. I don't know what the solution is. I get fearful.”

She is also intensely aware of the pain and conflict that this causes across the generations. “There's a great quote from Naipaul,” she explains. “I think it's from A Bend in the River when Salim says that he was not interested in ‘being good, as it is in our tradition, but in making good.’ I don't have that so much, because if you're Jamaican you don't have a language, you don't have a necessary faith, but the Muslim and Hindu children I grew up with feel that very strongly. I think it's a false dichotomy,” she adds thoughtfully. “There's no need for being good to be separate from making good.”

Difference is, she says, the central theme in White Teeth and “all those things which highlight difference.” For this reason she became fascinated by genetics. “I was trying to understand what difference is and with genetics you get a wonderful opportunity of seeing where it begins, the very first point at which it begins.” She read one “incredibly boring” book about onco-mice and cancer genes in mice and talked to “a lot of bright friends” in order to write the scientific stuff, but is still, with characteristic modesty, convinced that the science in the book is “incredibly bad.”

White Teeth is not only stamped with Rushdie's approval; it has been compared to him, too. It is a comparison Smith treats with caution. “I think some writers, not just me, feel that you're being compared to Rushdie or Kureishi just because there are Asian characters in your book, and if that's the case, it's a waste of time and a pain in the ass because there are thousands of books with white people in them and they're not all the same.” She does, however, agree that she echoes the playful, self-conscious, teasing tone of recent Indian fiction and, indeed, of Tristram Shandy.

“You either write the Austen book or the Shandy book,” she announces ruefully. “I don't like being on the side of Shandy, actually, and I hope I'm not there for ever, because I think it's a tough one. The Shandy side of things is quite hard to do well and a lot of books which try end up being very convoluted, very irritating, very self-conscious—and I know there are elements of all of that in White Teeth.”

Smith is nothing if not self-critical. The new literary magazine Butterfly, which carries authors' critiques of their own books, includes a coruscatingly self-deprecating review in which she concludes that “White Teeth is the literary equivalent of a hyperactive ginger-haired tap dancing ten-year-old.” When I ask her if literary success has changed her, she replies, seriously, that she needs “negative feedback” in order to move forward.

“I was very worried,” she reveals, “that if this book did well or was forced to do well by a lot of hype behind it, that I wouldn't write anything again. I don't like hype in general and I'd never imagined that I'd be the subject of hype and that's kind of a hard thing but as long as I think the book is fairly rubbish, then I know I can carry on writing better things.”

There is clearly about as much chance of this level-headed young woman becoming a literary prima donna as of the Conservatives winning the next election. At the beginning of the interview, she had seemed a little brusque, a little jaded already by journalistic questions about money and fame.

As she talked about the book and its themes, however, her weariness—perhaps shyness?—was replaced by animated arm-waving, eloquence and passion. She is, she admits, buying a flat of her own, but it's in home territory in Kilburn, where most of her friends don't care about the novel or the hype. “I don't think my life's changed,” she concludes with a rare smile.

“I think so far I'm doing about as well as you could expect from a fairly young person who has never had money before. I think I'm doing OK.”