Publishers love to find writers to label as "the spokesmen of their generation". The American, Bret Easton Ellis, became that and more when his first novel Less Than Zero was published in 1985 when he was just 21. It was hailed as a literary second coming. Now, 14 years on and featuring on university literature-courses, Ellis is still famous, and through the eight years he has devoted to quietly writing his new novel, Glamorama, has remained so.

During that time, Ellis might have become famous for being famous, but American Pyscho (1991) prevented that. It is a surreal odyssey into the mind of a serial killer, which shocked readers, suggested Ellis could give masterclasses in dismemberment, and inspired many attacks which owed more to the language of outraged sensibilities than literary criticism.

Sleek, shiny surfaces have always mattered in his fiction - never more so than in his new book, which is his longest and most ambitious: not only do his characters value only beauty, fame, designer labels, tans and well-toned bodies, they don't even see anything else. This is a world of drugs, vicious sex, loud music and technicoloured violence. In fact, Ellis's is flat, dead-eyed prose, avoiding metaphors and adjectives and aspiring only to description when the subject turns to either sex or disembowelling violence - or, frequently, both. The man himself stares blank-faced from his book jackets; not tough enough to be menacing, not weird enough to attract a second glance. Unlike his characters Ellis, with his large, pale, boy's face and short, receding hair, is unfettered by the disturbing physical beauty which makes life so difficult for his supermodels and poseurs.

Sweeping into a smart London hotel streamlined enough to provide a setting for his fiction, Ellis is very tall and, aside from his height, very ordinary looking. In his trademark long, black coat and conventional black suit he could be a Mormon on assignment.

He is animated and chattily remote, more confident than intimidatingly cool. He knows who's writing what, even if he hasn't read it. He is a fan of John Updike, whom he regards as "probably the greatest living American writer" and Don DeLillo.

Still almost two weeks short of 35, he looks and sounds middle-aged . . . he constantly refers to noise, loud music and his age. On having this apparent preoccupation pointed out to him, he pauses - as he often does before answering a question, and then explains: "I feel I've been doing this (writing, taking about writing) for a long time. Fourteen years. It seems like forever." If nothing else, Less Than Zero made him old long before his time. Then, "with this new book, I began it when I was 26 and all the time kept thinking: `Here I am, 26, and working on this' but when I finished it I wasn't 26 anymore. I was 34." Ellis is no longer wrapping himself in enigma - at least, not today. He has large, clear, greenish-brown eyes and a loud, good natured voice; his movements are big and awkward. If his of-the-moment social satire is intended to shock - and it does: he doesn't.

Some reviewers have decided his urgent, snappy fiction is pornographic. It isn't. True, at its most violent it borrows images from Jacobean tragedy, yet Ellis's fiction is ultimately a highly moralistic reading of a sick, vicious society. Victor, the empty, vain, sex-obsessed central character of Glamorama, is far from likable but as the novel unfolds readers not only sense his fear, we smell it. Considering the mixed reviews he has received this time, it would be understandable were Ellis to offer, on behalf of his novel, a defensive plea for understanding. He doesn't.

"Lots of people hate my books. Particularly in America, they don't like me, my books, my flatness of tone," he says. "They don't like the way I write, full-stop. But I have got used to this . . ." All of which is said in a pleasant tone of neutral good-will.

Where to place Bret Easton Ellis the novelist? More social commentator than storyteller, less linguistically adroit than Martin Amis, he is on the tough side of Jay McInerney and far superior to Tom Wolfe. Until now, plot has never drawn him. His sex scenes are disturbingly aggressive, impersonal and often bisexual. Ellis writes about what he sees and, as he says himself, "it's unlikely I'd ever write about the landscape". In his new book, the father features as a selfish monster, but then, fathers have never done too well in his work. Ellis admits to having been for a long time unaware of the role the father has in this book. "I was writing it over a very long time and I guess I came up against a lot of my demons. I had wanted to write about a conspiracy, so it sort of happened while I was writing the book." Midway through, Glamorama becomes a chaotic thriller. "Victor's father actually puts him into danger," observes Ellis with surprise.

His own difficult father died in 1991 at 50, and with him may have gone some of Ellis's problems. But Ellis is more self-protective than his easy demeanour suggests: "Victor is the least autobiographical of all my characters." This is probably true - Clay, the troubled young narrator of Less Than Zero, offers the best portrait of what the nervy young Ellis, complete with a couple of real-life nervous breakdowns, once was.

Born in Los Angeles in 1964, Easton Ellis is the eldest of three - "my sisters are 31 and 30". Home was a "smallish" house - with a pool - in Sherman Oaks in the San Fernando Valley, the New Jersey of the west coast. His parents had married young; his father was from Nevada and his mother from Chicago though she had grown up in Anaheim, near Disneyland: "Yeah, you could see the Matterhorn from her house." He did badly at school. His parents worried sufficiently to take him out of public school and send him to Buckley, a private school in the Hollywood Hills where he was "the last to be picked up and the first to be dropped". He was always interested in writing.

Legend holds he wrote his first novel at 10. Sounds like traces of Kafka and Roth . . . the central character wakes up to discover he has become a pancake. Young Ellis was quiet and disliked sport. "My grades were poor, I had no grip on math or science. I just wanted out of Los Angeles. Everyone was involved in either the television or movie industries and it was all drugs and sophistication. I felt if I went to college with the people I knew it would be more like four more years of high school than college."

Home life wasn't great. "My father drank a lot. He caused so much trouble. Mom eventually threw him out. I'm not trying to say I had an unhappy childhood or that I was traumatised or anything, but he caused a lot of unnecessary trouble. We were middle class, very conservative. It was a lot like the Ice Storm," he says, referring to Ang Lee's film of Rick Moody's novel. "Not that we were anything like the family. My parents didn't go in for wife-swapping, but it could easily have been L.A."

The Ellis family was comfortably off, but not rich. "My father did make a lot of money after they split up. What did he do? He - " grimaces and a series of gestures follow as Ellis makes up his mind exactly what his father did do. "He was not exactly but kind of a, well, he worked in real estate. You could say he was involved in the real-estate business but he didn't exactly sell houses." Was his family literary? "You know it's funny, when I was growing up, I would have said they were great readers. There were always books. Later, I could see the books at home were mainly best-sellers, popular novels, Stephen King, self-help books - like How To Be Your Own Best Friend. I realised this told me a lot about my parents and how their lives were at that time."

Ellis applied to various art schools and eventually ended up going to Bennington, a small, non-Ivy-League college in Vermont. The experience held far more than just a new school. It was foreign travel for a Californian. "Going East meant getting culture. It was wonderful. I met my first rich people, I mean real rich, old money. People with trust funds. Not nouveau riche like in L.A. where old money only dates from the 1930s. People with these famous old Eastern names and you'd ask them, `do you belong to that family' and it turned out they did." At first, Ellis was subjected to taunts of "cowboy" and, worse still, "Valley boy". "I did have a Valley accent," he concedes. The first two years were wonderful - "1982, 1983 - Bennington was the most exciting place. It was liberal and free and full of ideas." It was also pre-AIDS. "But then the last two years, it was as if a steel door slammed shut and it all began to change. All these earnest, uptight yuppie types arrived and it changed."

When talking about his writing, Ellis refers more often than one might expect to craft, technique and "the art of writing". Though a course project, Less Than Zero was more than that for him. It was something he wanted to write. How does he feel about it now? He groans, he grimaces and says: "There are so many things about it that I would change if I could. That's the thing about being a writer, the more you do it, the more you know what you are doing. When I wrote Less Than Zero, I didn't know what I was doing, I didn't know how to do it. But I think the dread and despair which were so much a part of me were the things that appealed to people." With its cast of drugged-taking, sex-crazed, spoilt, dangerous rich kids frolicking in a parent-free zone (when asked the whereabouts of his parents, one character replies "my parents? ... In Japan, I think . . . shopping") it is more a lament than an attack. Clay, the narrator, witnesses life around him with an increasing unease and alienation. Having returned home from Camden, the school in Vermont which also serves as the alma mater for several of the characters in Glamorama, Clay clearly wants to break free of his girlfriend and his pals, some of whom have already begun to indulge in the dangerous perversions which are central to the new book.

Although now critical of his first novel, Ellis does not resent it. "I'd love to play the victim, but I can't. I appreciate it very much. It did a lot for me. It made it easy for me, easier to write." His family's reaction was different. "My mother was horrified, she didn't want anyone to think we were like the people in the book or that she was the blonde, drugged-out mother," he laughs. The reaction in Bennington was better - he became cool. In his youth, there had been no sporting triumph; no exam success. Suddenly he was famous. "You know it was only later I realised how much my peers resented it. At the time they were smiling but they told me later how much it bothered them. `We were smiling but we were really gritting our teeth.' It did put pressure on them, far more than it did on me," he says with obvious pleasure.

The success of Less Than Zero also inspired Ellis's father to re-establish contact, which the writer resented. Two years later, Ellis experienced the reverse side of success when The Rules of Attraction, a mannered campus romance complete with a chapter in French, proved a relative critical flop. By the late 1980s, Ellis was in danger of becoming a writer who was photographed more for being drunk and/or stoned in nightclubs than for writing novels. The next stage of his career arrived with American Psycho, a novel which caused outrage but ironically has secured his place as a chronicler of an amoral society virtually tearing at its own entrails.

In a viciously coherent narrative depicting an empty society inhabited by bored designer-clones engaging in mindless conversations about clothes, Ellis confirmed exactly how moralistic his view of life is. Society is the central character; Patrick Bateman, the narrator, is merely a product of that society, one in which no-one thinks, no-one listens, no-one cares. The narrator's concerns are divided between fretting about his clothes and mulling over his latest act of cannibalistic mutilation. As has become characteristic of Ellis's prose, his flat tone changes gear only during the vividly-described torture, group sex and dismemberment scenes.

The novel does shock - although often, at its most brutal, the sheer cartoon excess borders on the comic. Calm and smiling, Ellis sees himself as reporting on the evils of which society is capable. "My first books were more journalistic, I think I have moved closer to story. Certainly this one (Glamorama) is the closest I have come to a plot. When I began writing I liked to think `Hey, I can do without plot'; now I have changed my mind." At its most explicit, American Psycho does make the reader experience voyeuristic shudders. But is it a pornographic book? Ellis pauses, thinks and asks: "What is pornography?" It's a good question. The conversation then moves to J.G. Ballard, one of the most original of living writers. Ultimately, American Psycho confirms it is society which makes such books possible and Ellis's novel remains as real as shame, cruelty and all the other depraved things humans do.

Of American Psycho, though, there remains the possibility that Patrick Bateman's obscene crimes are confined only to Bateman's imagination. After all, there are no newspaper reports and for all the rivers of blood shed by Bateman's victims, the only person who seems to notice is the old lady at the Chinese laundry. Ellis's reaction is predictable: "Could be. But I'd never commit myself on that. I think it important that fiction is left to the reader. I like finding out how a reader interprets a book, it affects the way a writer comes to understand it."

Since 1987, Ellis has lived in New York, where he says he has a quiet life and remains a Californian. "My friends are writers and journalists, we work the same kind of hours and now that we're getting on we avoid loud clubs and techno music and go to the kinds of places were we can hear ourselves talk." Drugs are no longer as vital. He says he goes to the gym but does not yet look as if exercise is central to his life. "There is no wife, no children, no dog. It's all very quiet. I write." His wild days appear to be over. How wild were they? "Oh, I like to think when I was bad I was really bad."

Settled now in premature middle age, the disarming mildness with which Ellis faces even his harshest critics falls just short of philosophical. His books count because of the sharpness of their social comment. On recovering his long coat, preparing to leave, he wraps it about himself, almost completing in a single movement an unconscious and untidy pirouette.