I was rounding the bread aisle in Sainsbury when I came across three young women in mid-conversation. “He ripped off his fingernails,” said the first. “And nearly pulled off his ear,” added a second. “Who could do such a thing?” said the third, and they all shook their heads in what's-the-world-coming-to despair. But their eyes were lit by other emotions: excitement, titillation, glee.

I'd guess the graphic detail in the reporting of Baby P's death has provoked three distinct responses. Those repelled and sickened, who turned the page, unwilling to have scenarios of a Nazi-obsessed thug torturing a toddler in a filthy flat playing, unbidden, in their brains when they look upon their own children. Secondly, those who feel a grim, moral obligation to stare unblinkingly at all evidence. And then people who to varying degrees - although they'd never admit it - get off on this kind of gore.

Did we really need that virtual-reality, battered-infant graphic to understand the magnitude of Baby P's suffering? The jury did, of course, and rather that than the post-mortem photos judged too disturbing to show them. But are the rest of us so devoid of imagination and fellow-feeling that we cannot comprehend such horror or want to depose Sharon Shoesmith, director of Haringey Children's Service - inspiring motto: “you cannot stop people who are determined to kill children” - without exposure to a computer-generated corpse?

All week I've been arguing about this with my husband, a long-time newsman. The gory specifics were vital, he says, because without them Baby P would be a generic death, just another hapless, who-cares underclass casualty. That computer image might upset me, penetrate my safe little bubble of nice. But so what! It shocked the nation out of complacency, and put neglected children into Prime Minister's Questions.

Maybe so. Perhaps motherhood just lowers one's threshold for dead kiddy material. Pre-children I found the movie Trainspotting darkly hilarious. Today no one could persuade me to watch the scene in which a drug-addict's baby dies of neglect.

Certainly those this week who took one look at the photos of blood-soaked Babygros and closed their newspapers were mostly women with children. The anguish that many mothers feel on seeing such stuff is so strong and visceral that it makes them angry, not only with the wicked folk who commit the crimes, but those who insist on shoving it beneath their eyes.

Upsetting and alienating women does nothing to help protect more potential Baby Ps. Indeed I wonder to the contrary whether lurid and salacious detail doesn't distance us altogether from actual suffering, by turning a human tragedy into a modern penny dreadful.

In any case, such a style of reporting is not a given, a necessity, but a reflection of fashion, a recent growth in the public appetite for horror. Compare a movie certificated 12A (suitable for accompanied children) a decade ago and one made this year. In the Nineties, a 12A rating foretold a minor curse, a bit of smut, maybe some bloodless biff and pow. Today designated family viewing may, like Casino Royale, have a graphic and drawn-out murder or, as in The Dark Knight, show a pencil shoved in a man's eye.

Likewise court reports of the James Bulger case of 1993, in which a child little older than Baby P was murdered by two older boys, chronicled his suffering. But some facts related to acts of sexual abuse, along with more graphic detail about how he met his death, were deemed too upsetting for publication and came to light only later in books and documentaries. Yet somehow, without even a simulacrum of a dead James as a teaching aid, Britain still managed to take in the full horror of his demise.

At what point does the cause of verisimilitude produce a form of violence-pornography? There is undoubtedly a huge appetite for stories of suffering children. Perhaps, as with horror movies, we get a kick from the adrenalin surge of our own shock and disgust. Maybe such tales play to our dark side, the bit of our psyche that would pull wings off insects, suppressed beneath a patina of civilised behaviour.

Dave Pelzer's bestselling memoir A Child Called It showed that millions of us will pay good money to pore over accounts of a child whose mother fed him dog faeces and ammonia, froze him in icy baths, stabbed, burnt, starved, gassed and locked him in a basement. How many more thrillers, or even TV series plotlines, must I watch in which the inevitable thrilling denouement - shock-horror-yawn - is the sexual abuse or death of a child?

A lascivious pleasure in the torture of innocents fuels Japanese manga comics, children's fables, Virginia Andrews's Flowers in the Attic - in which incarcerated siblings eventually engage in incest - even the gothic misadventures of Lemony Snicket. You see the same voyeuristic delight in child-in-peril news stories: Madeleine McCann, and in that Austrian cellar, of course.

But also the Jersey care homes child-abuse saga. This week, as the police admitted that their excavations had found no human remains, it felt as if public hunger for the macabre, unslaked by mere verbal accounts of cruelty, had tried (and only just failed) to whip up a torture chamber and a charnel house. There was palpable disappointment that a supposed fragment of a child's skull turned out to be coconut husk. And as a jury heard allegations that Shannon Matthews, aged 9, was drugged and tied to a beam with a strap, a frisson vibrated across the internet.

Indeed the web, with its one-click crudity and amoral horrors, justifies all abnegation of good taste. In that world without secrets, unpalatable, edited-out details will pop up there anyway a nanosecond later. “Unimaginable cruelty” said many headlines to describe Baby P's fate. And that is how some cruelty should be left. We must be sparing with horror. Images and words that shock us into reaction also, over time, desensitise us.

Otherwise why stop at a still image? Why not create a Jason Owen avatar, have his animated fist pull back for that final, fatal blow, baby blood spattering, milk tooth flying. Maybe then we'd really, truly feel Baby P's pain. It would be a guaranteed hit online. After Second Life comes Second Death.

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