The other week, travelling by train from London to Lancaster, I was blessed with the experience of sitting across the aisle from two London lads, laden with beer, on their way to Blackpool for a piss-up. It was their first time up North. "Where's the mills?" they kept shouting. "Are we up North yet? What's this? Warrington? Is that in Sheffield? Why isn't it raining?" Every time our friendly train manager announced his presence, they fell about in gales of bellowing laughter because he had a Wigan accent. It was still killing them when they changed at Preston.

The other week, travelling by train from London to Lancaster, I was blessed with the experience of sitting across the aisle from two London lads, laden with beer, on their way to Blackpool for a piss-up. It was their first time up North. "Where's the mills?" they kept shouting. "Are we up North yet? What's this? Warrington? Is that in Sheffield? Why isn't it raining?" Every time our friendly train manager announced his presence, they fell about in gales of bellowing laughter because he had a Wigan accent. It was still killing them when they changed at Preston.

They were nice boys, if loud, and their laughter was fond. Let's hope things came up to expectations. No clogs or shawls, I'm afraid, but we can still muster some lovely picturesque cobbles and alleys. I hope the rain obligingly showed, lashing the seedy Golden Mile, and that the girls had fag-dangling mouths and curlers in peroxide hair.

The thing about a stereotype is that you can always find examples to prove it's true. The other thing, of course, is that it's a truth, not the truth. But we love to simplify. I have been writing for years and my novels are set all over the place, but now that I've written one about a family's progress through almost an entire century in my home city of Manchester, the sigh of recognition from people in the publishing industry is almost palpable. Ah, at last! A category! Northern working class family saga! Now we all know where we stand. This is great from a marketing angle, but it's slightly bemusing to suddenly find that everyone who wants to talk to me about the book wants to focus on the fact of my "northern-ness". It seems I've acquired an identity.

I've lived more out of the North than in it, as it happens, but never mind. I know from living in other places how people who've never been there (and a few who have) like to see it. Ergo, North comes in two types, Hovis and Grim.

Hovis is sweet little boys with hobnailed boots and caps too big for their heads, plucky factory girls with gorgeous hair making good, bullying mill owners with caddish sons, honest working men, the nobility of labour, Gracie Fields singing Sally, and matchstalk men and matchstalk cats and dogs. Hobson's Choice resides here, as does Catherine Cookson, and to some extent Walter Greenwood's Love On The Dole. Hovis is the old tradition, and very fine some of it is. It isn't trendy, however, and some good writers have got stranded here and never emerged. A few years back I looked for Louis Golding's Magnolia Street, an excellent book about the poor Jewish quarter of Manchester. The library finally got me an old paperback with a romantic cover, all gold embossed fancy lettering, the kind of thing your average literary fiction reader passes over without a glance. Who else languishes here, all unseen? But Hovis did exist, and I do believe that once upon a time in the north one or two people did actually get happy. But for a writer to portray happy northerners is to run the risk of falling into the dreaded 'Heartwarming Shite' category. (Ee it were tough but we were 'appy!...)

Grim is far more respectable. True Grim was foreshadowed by Kitchen Sink of the late Fifties/early Sixties. Some fine stuff here too from the likes of Alan Sillitoe (The Loneliness of the Long Distance Runner and Saturday Night and Sunday Morning), Stan Barstow (A Kind of Loving), and Sid Chaplin (The Day Of The Sardine). Northern working class fiction always translated well into drama, and some books have been superseded by their film versions. This was when I first saw on screen people and landscapes I recognised. A Taste of Honey rang the most bells - the girls' school at the beginning could have been mine. And so did some very early Coronation Street, before it turned into a silly sitcom. Ena Sharples really did look like my grandma, hairnet and all. Keith Waterhouse's Billy Liar caught the grimness, but the humour too, and his wonderful, forgotten There Is A Happy Land is one of the best books about childhood ever.

Now a fanfare for the real daddy of Grim, Ken Loach with Kes. My god, is it ever grim up north whenever Ken Loach has anything to do with it. From the opening sequence where that poor sad peaky little boy wakes up in the dark and calls his brother awake in tones of abject sorrow, it's pure hell. Am I really the only person ever who hated that particular mix of misery and sentimentality that was Kes? Loach put stuff on screen that had never been there before, and he finds wonderful actors. Martin Compston's stunning central performance ensured that last year's Sweet Sixteen was a far, far better film. But Loach is just as much genre as Catherine Cookson, and his unbearably bleak vision is just as predictable. Forty-five years ago, Arthur Seaton's rallying cry was, "Don't let the bastards grind you down." Loach's characters squirm under the heel, helpless. Nothing at all wrong with thoroughly mining a narrow seam, countless writers and film-makers do it. What is disproportionate is the influence of this one narrow seam. Read City Life's books of Manchester short stories, and you'll find about 80 per cent of the subject matter is disaffected youth, violence, drugs, bullying, abuse etc, all of which are vitally important subjects for fiction but not the only ones.

So what is the real north? Now that Liverpool has been named European Capital of Culture for 2008 and Manchester has officially been named best place in the country to live by the think tank Demos, how stands it with the dirty old towns? And why, in spite of the fact that writers and film-makers have steadily been producing good, multi-dimensional representations of the north for years, do the old clichés cling so fast? TV drama has been particularly fruitful in this respect. Think of Alan Bleasdale's Liverpool-set GBH, Manchester's Queer as Folk, Newcastle's Our Friends in the North. All showed a fuller picture of the modern north. On film? East Is East was a perfect mix of comedy, pathos and seriousness. Even Billy Elliot, derided as a lowbrow Kes with a happy ending, caught something. It's a lovely irony that Martin Compston's own real-life story (working-class boy transcends his roots through sheer force of talent and personality) owes more to Billy Elliot than it does to Kes.

The reason the clichés cling fast is romance. This applies to both Hovis and Grim, sentimental simplifications both. The Manchester I remember was always more than its images. Neither victimhood and bitterness, nor a soft sentimental ee-by-gum glow prevailed, though both existed. It was grey and grimy and some terrible things happened to some people. It had beauty. People were diverse and full of life, some were happy, some were not, and there was humour. Where now do I find flashes of a north I recognise? The music of the Smiths, the markets of Fifties Manchester in Howard Jacobson's The Mighty Waltzer, 24 Hour Party People, odd bits of The Royle Family, the scene in Mike Leigh's Naked where two Mancunians in London, Johnny and his long-time ex-girlfriend, down and out, hopeless, lean tiredly together and sing the old proudly Hovis ditty - "Take me back to Manchester when it's raining, I want to wet me feet in Albert Square" - sentimental but getting away with it because the tone's just right and by this point in the film they are both full characters and not just bearers of social roles. Context is everything. Then I go back years to a scene remembered from Shabby Tiger, a book by Howard Spring, the only "Manchester writer" I was aware of when I was growing up. Actually, the scene might not be anything like this; you know what memory's like, and you never see his books now even though they used to lie around in people's houses, so I can't check; but here's how I remember it: the shabby hero stands on Market Street on a busy day, and I think the sun's shining, and he suddenly bursts out with some corny speech about how bloody marvellous Manchester is and the only place in the world to be. I read that when I was about 13 and still remember it.

The North that's really there when you get off the train, the North where I was born and brought up and to which I returned after long absence is just a place full of ordinary normal twenty-first century people living out their ordinary, complex, infinitely weird, wonderful and unexpected lives. I hope you had a fantastic time in Blackpool, lads, and I'm sure you created your own North around you wherever you went.

'Turn Again Home' by Carol Birch is published tomorrow by Virago, £17.99