You can judge a book by its cover

You don't catch Saul Bellow cosily telling you about his hobbies on the dustjacket

SO YOU have finished writing your book. The publisher has proofed it up. The blurb is done. You learn from it, to your modest surprise, that your book is the product of a wonderful new voice. And this is the case whether you have written a biography of Merle Oberon, a slim memoir abusing your ex in viciously personal terms or a novel in which a Cambridge undergraduate gets up to all sorts of hilarious scrapes while trying to buy contraceptives.

Sooner or later you are going to have to let the world judge what it thinks of the book - and of you. But, before that, you have one last chance to influence your readers, to say "please be nice to me, or, at least, please be interested in me". In other words, you have your author biography to write...

"Roland L Bessette, an attorney specialising in labour and medical malpractice defence, has a degree in journalism from Wayne State University and a juris doctorate from Detroit College of Law. His interests include music, wine, photography, weightlifting, European travel and Hemingway. He lives in Grosse Pointe Park with his wife Phyllis, a physician. They have three daughters."

This perfectly genuine example of a terrible author biography turned up this week on the back of a new book. Above it is an unmissable photograph of Mr Bessette - he is shown wearing a dinner jacket in a multi-storey car park. The more you contemplate the author biography, the more pleasures it begins to yield. I don't want to make fun of Wayne State University and the Detroit College of Law - no doubt both excellent institutions - but you do start to wonder what led an author to share with his readers his qualifications, his wife Phyllis's job, his interest in weightlifting and wine and his address. I expect it is an attempt to get the readers and reviewers on his side; just as hostages in war zones are always advised to start telling their kidnappers about their families to make themselves seem human, so the critics will be less inclined to be rude about a book if they know that the author has three enormous daughters and a wife, Phyllis, a physician, all eating their heads off in Grosse Pointe Park, wherever that may be. The book, incidentally, is a life of the tenor Mario Lanza, and a tenth as interesting as Mr Bessette's biographical sketch.

The golden rule is that the smarter the author, the more austere the biography. You don't catch Saul Bellow cosily telling you about his hobbies on the dustjacket. And, as authors rise up the scale of esteem, the biographies tend to become briefer. Martin Amis used to chat cosily about his double first and being educated at "a series of crammers"; these days, however, it is as stark as Thomas Pynchon's and merely says: "Martin Amis is the author of nine novels, two collections of stories and three works of non-fiction. He lives in London." Come on, this says; I don't need to tell you who I am. There's nowhere much to go from here; perhaps "Martin Amis is a novelist" or even "Martin Amis exists".

I can't help rather regretting this tendency, which has spread down the scale so that even comic novelists just tell you the names of their previous novels, any prizes, and the county they live in. The appallingly fascinating way they once habitually referred to themselves by their first name and infallibly listed every previous job, from arms dealer to usherette, used to be a great source of pleasure, a constant restful temptation when the novel itself grew tedious.

It was once a useful litmus test; if the author biography turned out to be significantly more interesting than the novel, then the reader might as well give up immediately. But now you have to rely on other tests, and it is not often that a dedication or a copyright page will tempt a flagging reader.

So when an old-fashioned terrible biography turns up, let's enjoy it while we can. A superb example arrived last year with a comic novel about holiday reps in Ibiza. The novel itself was an utter nullity, but the biography was a joy. "Colin is a direct descendant of the Russian Royal Family... selected by Nasa in 1984 to join their space programme. Six months into training it was discovered that he suffered from horizontal vertigo... spent a number of years working with dolphins. He specialised in monitoring the emotional stress and psychological traumas that these mammals undergo... Since the closure of Windsor Safari Park, Colin has divided his time between Formula Two race driving and lollipop man duties near a school in Peckham."

Colin may not be up to much as a novelist, but one thing is clear: for the specialised and exquisite genre of the author biography, this man has a perfect talent.