In a week when the respective trials of some sleazy journalists and a groping celebrity reached their dramatic, depressing conclusions, there has still been room in the press to discuss the sex life of Caitlin Moran. Indeed, Moran’s glancingly autobiographical novel How To Build a Girl, and the mini-hurricane of author interviews which have accompanied it, have proved to be the perfect antidote to revelations about Andy Coulson and Rolf Harris. By invading her own privacy, Moran reveals the pathetic absurdity of hacking, and any groping that happens in her book is done by her – to herself.

Much of the sex in How To Build a Girl is of the solo, one-handed kind, to the extent that an early reviewer predicted that it could become the Portnoy’s Complaint of the post-feminist generation. Eschewing the traditional line of self-defence used by authors on these occasions – it’s fiction, I made it up – Moran cheerfully told one radio interviewer, “I want to masturbate my fingers down to the bone.”

That is the Caitlin Moran approach: the best way to defeat the ranks of idiocy and humourlessness is through laughter and honesty. Much of her advice in the past has consisted of letting women into secrets men have known for years: “Just fake it ’til you make it” summarises much of male history. More daringly, she will take what is perceived as a gender flaw and reveal it as a strength. “That’s what women do, isn’t it, say things out loud, try it out? They don’t know what they think until they start.”

So it has been with self-groping. For male writers, this ridiculous, near-universal activity has been a source of humour and insight since Philip Roth accorded it literary and comic respectability in Portnoy’s Complaint. It inspired some of the best jokes in Martin Amis’s novels (“In the end, you’ve got to hand it to hand jobs. They’re deeply democratic” – John Self in Money). It appears so regularly in the work of Geoff Dyer that it is rare to finish one of his books without encountering at least one scene in which the author gets busy with himself.

The subject, indeed, is something of an obsession with writers. It is a recurrent theme in the letters and work of Flaubert and Balzac. Joyce’s Leopold Bloom wondered whether the words “At it again” would be written on his tomb. Anthony Burgess often claimed that writers were at it like monkeys. More startlingly, John Fowles once wrote , “One can no more think of making fiction without onanism ... than of the sea without waves.”

Usefully for a writer – or film director – it is one of the few sexual activities which still retains the power to shock. A scene in the recent sitcom Episodes which showed a TV executive feverishly tugging away at himself packed far more of a comic punch than any conventional, predictable coupling could ever do. By contrast, the female version has never quite escaped from the elegant, erotic, soft-focus, Fingersmith approach. It has had its champions, like the American Betty Dodson, who wrote Sex For One in 1973 and still, at the age of 85, runs Bodysex Workshops. But it has taken Caitlin Moran – single-handedly – to depornify it.

Moran’s great strength seems to derive from the fact that she, like Julie Burchill and Suzanne Moore, has written her way to success from a working-class background. That journey has brought with it a cheerful, nothing-to-lose confidence, oddly reminiscent of Germaine Greer, Barry Humphries, Robert Hughes and Clive James, the four Australians being portrayed in Howard Jacobson’s current TV series Rebels of Oz. These writers, arriving from the outside, bring a much-needed note of irreverence, wit and good sense to a cultural scene still dominated by middle-class Englishmen playing with themselves – and not in a good way.

John Bercow, meet Randy Newman

Soon after its release in the late 1970s, a song written and performed by Randy Newman was debated in the Maryland state senate. It was argued that the song, “Short People”, was so prejudiced that it should be banned from the radio airwaves. With genuine bewilderment, Newman defended his composition in interviews, pointing out that, far from encouraging bigotry, it was meant to be satirising it through irony.

To judge by recent comments made by the Speaker of the House of Commons John Bercow, “Short People” is unlikely to be among his personal desert island discs. “Whereas nobody these days would regard it as acceptable to criticise someone on grounds of race or creed or disability or sexual orientation, somehow it seems acceptable to comment on someone’s height, or lack of it,” he said a touch primly. It was “low-grade, intellectually substandard and schoolboyish”.

Of course, he is right. Prejudice based on physical attributes – shortness, fatness, agedness, baldness – is cheap, stupid and often bullying in tone. That is precisely why the sensible approach is to take the Randy Newman line, and mock the bigots.