SHE PERCHES tidily on the edge of the sofa, delicate and watchful as a little bird. Despite her height, Joyce Carol Oates seems tiny and infinitely fragile, with a ribcage as narrow as a child's, within which one imagines a nervous, racing heart.

Her exquisite sensibility would be more appropriate to Emily Dickinson (whom she strangely resembles) or Elizabeth Barrett Browning than to a highly-regarded writer whose fiction tackles the toughest and most controversial aspects of US life. Oates has published thousands of short stories and almost a novel every year since 1964, and today her name is breathed alongside those of Updike and Bellow.

Macmillan publishes the latest of her 21 novels this week. The most recent is Black Water, a novel based on, but not about, the incident in 1969 when Ted Kennedy drove his car into a creek, trapping and drowning Mary Jo Kopechne, the young woman who was his passenger. Oates's novel is set in the present day, the characters re-named. Why had she chosen to retell this much-told tale?

'I have written the only work focused exclusively upon the young woman. All the focus at the time of the original incident was upon Ted Kennedy and how this would affect his political future, or upon the police or the prosecutor. A young woman suffered and died a very horrific death, but that was almost forgotten. It became a matter of men sparring with one another.

'I didn't want the book to be tied to a single event. Chappaquiddick is part of our contemporary mythology, so one can use just the outline and not the specific history. I wanted to write about idealism and innocence betrayed, and our misplaced faith in our public men. I guess you can only be disillusioned if you have ideals, so it was also about the extreme disillusionment young people felt about politics.'

What about the much-vaunted ideals promted by the 'family values' and 'pro- life' campaigners? 'These are smokescreens, not ideals. Our radical right is very dangerous because they try to define the US in their own image. They have been in power for three administrations, but now we have a new atmosphere and it seems possible that Bill Clinton may be elected. I say that in a spirit of cautious optimism.'

She is the only author I have ever met who seemed genuinely reluctant to talk about herself and her work. 'The things we say about ourselves are extremely provisional and theoretical, and yet they're taken to be truths. When people praise my books I always feel they're saying it because they're nice people, and that I should thank them for their generosity.' If this sounds like mock-humility on the page, it was perfectly convincing when she said it. She kept deflecting my questions by asking about me, my children, my cat, so that I had to wrench the conversation back to its proper subject - herself and her books.

Joyce Carol Oates's work is now taught in North American and British universities, usually under the general heading of women's studies. I asked whether she welcomes this: surely good writing is just writing, neither masculine nor feminine? 'It seems wonderful that anyone should take an interest in one's work.' she answered. 'In very recent decades women writers were simply not considered at all. It was a male pantheon into which one or two women were permitted to tip-toe: Elizabeth Bishop and Marianne Moore. Now that we have a category of women writers, it's like a neighbourhood; a community to live in.'

Calm, serene and soft-voiced, Oates is slow in her movements though always perfectly lucid in her responses. After the interview had proceeded politely and efficiently for an hour, she came alive when I asked about her book On Boxing: on the face of it, an unexpected subject. 'Fundamentally, my motive and interest lay in writing a book about failure and how men contend with it. Failure is inevitable in a boxer's life, and boxing is about having the courage to confront that failure. When I was writing it in 1986 Mike Tyson seemed invincible, yet he rose and fell so quickly. He won the world title, married, had a number of personal catastrophes, and lost it - all in a few years.'

Was she conscious of employing a specifically female language, with different rhythms and subtexts? 'I don't have any political agenda or any identity as such; I just wish to explore my own self, and we all have part of the other gender in us. But if I am writing in a man's voice, then I have to modify the language. The man I'm writing about now - based on a relative - is neither literary nor intelligent: he is a man of action, a sportsman, gambler, man-about-town. Creating him meant getting inside the mind of a man who uses the vernacular, who is very profane and funny; and getting those sentences the way I want them is a challenge.'

It may seem surprising that the exquisitely refined Ms Oates should have such a raffish character in her past, but she is the first member of her family to go to university, and proud of the parents who made this possible. She was born at the end of the Thirties, during the US Depression. 'I come from a background in which there was not much money and my parents were victims of the recession. My father had to start work at 13, and my mother dropped out (of school) after eight grades, aged 14. My parents never made it to college, not because they could not have done so, but because they had to start earning money.

'They are both still alive, I am glad to say, and splendid people. My sister, who was born 18 years after me, is autistic. At first she was considered to be schizophrenic or retarded; a later theory blamed it on the mother. Today it's believed to be a biochemical imbalance that causes autism. So my parents have had severe problems that have not affected their positive attitude to life. My writing is, at least in part, an attempt to memorialise my parents' vanished world, my parents' lives. I try to write about people who emulate them.'

Brought up on her grandparents' farm in Millersport, near Buffalo, she witnessed a community in which violence and catastrophe, drunken husbands, brutal fathers, despair and bankruptcy were all familiar. Its redeeming feature was an enormous, marvellous teacher, of whom Oates has written: 'Our school was an old wood-frame, one- room schoolhouse in which eight quite disparate grades were taught, and taught very capably, by a heroic woman named Mrs Dietz. I remember her emphasis upon such time-honoured pedagogical exercises as penmanship, memorisation, sentence diagramming, spelling. I remember her deep seriousness, her zeal in her calling, her very teacherliness.'

'I was very fortunate,' she adds now, 'to be spared the discrimination against women and girls that some of my friends came across in the Forties and Fifties. Also, Mrs Dietz focused upon spelling and grammar and I responded to that. I'm very interested in words. I can sit and read the dictionary.'

She sits, demure and poised, hands clasped in her lap. My elderly cat - normally suspicious of strangers - curls up against her, utterly relaxed. This is so unusual that I comment on it. 'Oh I just love cats] We have three cats, and I'm missing them.' I begin to relate how I rescued this same purring cat as a kitten from cruelty and neglect. 'Oh, stop]' says Ms Oates. 'If you go on I may cry]' Looking at her, I can see that she may indeed. I stop. She strokes the cat, who tucks her nose in deeper.

I ask whether her own success is a burden or a pleasure? 'The word 'success' may be a bit of an overstatement,' she demurs. 'I'm not really a commercial writer. My novels have a steady and predictable sale, but are rarely in the best-seller lists. Black Water was on some lists in the US, I believe, but I would be very shy of asking my publisher what that means.' This remark, which sounds intolerably miss-ish, is evidently the truth. When my telephone rings and the voice of the caller on the answering machine fills the room, bold and unaware, Ms Oates freezes with embarrassment. 'That's why I could never use an answering machine,' she says. 'I would always imagine the person was there, listening to me and . . .' And what? Laughing?

How can she bear to expose herself to public scrutiny? She has been married for 28 years, but she doesn't even like her husband to read her work. 'He sometimes sees it when it's ready to go out, but more frequently he doesn't read it at all. I need a private space for my imagination. If I thought anyone was going to read it, especially the same day . . . Once in a while I re-read my earlier work, usually because I have to write a preface for a new edition, and, across an abyss of years, I am quite taken by the energy that seems to reside in the novels.'

That must be the key to Joyce Carol Oates. Despite her apparent fragility, she is a tough chronicler of contemporary life, dealing with the great American themes of money and greed, colour and class (especially the under-class), but all her energy goes into writing. This strangely touching, waif-like figure seems exhausted by the effort. 'Life is energy and energy is creativity.' she says. So did Balzac. The two could hardly be more different, yet each set out to describe the human condition of his or her time and nation. The comparison is a measure of her stature.

'Black Water' is published by Macmillan, pounds 13.99.

(Photograph omitted)