Scarlett Thomas: There's no point in turning over. Big Brother is on every channel

You can ignore them. You will forget them. But they're here to stay

When Big Brother was first announced in 1999, I had just finished writing a novel about some young people who are confined on a remote island by an unknown captor. The point of the novel was that these people, faced with a big question about why they were prisoners, in fact ended up sitting around talking about sex, TV and their aimless lives. Obviously, I wasn't overly impressed to discover that my idea was about to be gazumped by a TV show. My book wasn't scheduled for publication until after the first Big Brother had aired, which meant I had a whole summer to listen to people saying things like "What a good idea! Get some people and confine them in a house - brilliant TV!".

When Big Brother was first announced in 1999, I had just finished writing a novel about some young people who are confined on a remote island by an unknown captor. The point of the novel was that these people, faced with a big question about why they were prisoners, in fact ended up sitting around talking about sex, TV and their aimless lives. Obviously, I wasn't overly impressed to discover that my idea was about to be gazumped by a TV show. My book wasn't scheduled for publication until after the first Big Brother had aired, which meant I had a whole summer to listen to people saying things like "What a good idea! Get some people and confine them in a house - brilliant TV!".

I felt too sick to watch it at first, just in case I really did end up seeing my book on screen. And I felt disturbed, too: these were real people, not some made-up characters in a book. I wondered, like everyone else, whether this was legitimate entertainment. But, also like almost everyone else, by the end I was watching compulsively, willing the lesbian nun to triumph over the Oasis-loving builder who never read books.

It would perhaps have been OK as an experimental one-off. But, as the fourth series of Big Brother launched on Friday, it has become possible, yet again, to examine the programme that became a template for most of the mundane TV that is now the bulk of mainstream entertainment. Not that it will be examined by many people. Now that so much prime-time TV is based on the reality TV format of doing strange things to real people (or their houses) it seems unlikely that many commentators will bother to open their laptops to write another piece either ironically celebrating the banality of this form of entertainment, or criticising it for being so cheap and predictable.

"Reality" TV is no longer the mildly titillating, vaguely sociological spectacle we were originally promised when the first Big Brother aired. As well as the now familiar close-up-for-the-tears spectacle of the prime-time makeover or talent shows, there are now 24-hour cable channels devoted to such treats as When Good Pets Turn Bad, and Real Life Rescues. But the chattering classes haven't been watching - or chattering - about these things for a while now. By the time the third Big Brother aired, it had become fashionable to say things like "Who on earth is Jade?" as she appeared in Frankenstein's monster form on the cover of the tabloid newspapers that seemed to be attempting to incite a whole nation to hate her.

It seems odd that we once cared about the smallest psychological scars that these programmes might leave on their fragile amateur casts. Now, in the latest twist, two of the new Big Brother contestants could win almost as much money for having sex on TV as they could for winning the competition. The Sun (of course) has perhaps created the most revolting potential chat-up line in history: "Do you want to go halves on 50 grand?" Classy.

Remember the start of the National Lottery? In the first week, you could barely move for people talking about the moral implications of it all. Were we about to turn into a nation of casual gamblers? What would you do with the money? How much of it would you donate to charity? Now, no one cares. And when reality TV first started people did have sensible debates about voyeurism, celebrity and the psychological implications of sending an "ordinary" person on the now well-trodden path - from nobody to tabloid-front-page material and then back to nobody again - in the space of one summer. But what difference did any of it make? Is it now simply a normal part of the life-cycle of a cultural product to be debated and rejected before going on to become so successful no one bothers to criticise it any more? Perhaps it's down to the short attention spans of the chattering classes, but they never seem to chatter about anything long enough to make it stop.

And as for Big Brother 4? While millions of people text message their votes, and a few thousand fashionably yawn, tabloid monsters will be created and delicate hopes of celebrity will be ripped apart like old rags. And there's no point in changing channels, either, because the same thing is on on the other side. Perhaps there is still something to be said about reality TV after all.