Why do most American detectives lead such grim lives? Why do their relationships get nowhere, why don?t they have friends, why do so many of them descend into alcoholism? Why are all of them such lonely and flawed men?

The British sleuths, by and large, have steady personal lives. Sherlock Holmes, Hercule Poirot, Miss Marple and Lord Peter Wimsey were odd people in their various ways, but their private lives were smooth. But look at their brethren across the Atlantic, and they are, outside their work life, horror stories.

Just three examples. First, Lew Archer, created by the much-underrated Ross Macdonald (The Chill is perhaps the best detective novel I have ever read). He is a man who quit the Los Angeles police force on moral grounds, whose wife left him because she was fed up with what she considered his impractical uprightness. Archer is a profoundly lonely man looking for love, yet nearly every case he handles deals with the rotten cores and dirty secrets of apparently happy families.

Then there?s Lawrence Block?s Matt Scudder, an alcoholic ex-NYPD cop who left his family after accidentally causing the death of a young girl. The series begins with Scudder deep in alcoholism, living in near-penury as a private eye without a license. He spends a lot of time in church alone, praying and looking for absolution. As the series progresses though, things get slightly better.

In the fifth book, Eight Million Ways To Die, he joins the Alcoholics Anonymous, and from the next one onwards, he doesn?t touch a drop, but continues to attend AA meetings, because he feels the urge all the time. He even falls in love and marries, but since this is American detective fiction, it?s slightly complicated. His object of affection is a hooker, and it takes three books of him struggling to come to terms with this, before he can finally tie the knot.

But James Lee Burke?s Dave Robicheaux possibly has the saddest life among all his colleagues. We meet him for the first time when he is fighting alcoholism with the help of his second wife Annie (his first gave up on him years ago). He is a Vietnam vet and former New Orleans cop who is eking out a living running a fishbait shop. Then Annie is brutally murdered. He meets Bootsie, his teenage love, now a widow, and marries her, but she suffers from the fatal disease of lupus. Given to violent bursts of anger, extreme feelings of guilt and of course, the urge to drink himself unconscious all the time, Robicheaux constantly attends AA meetings. Some books later, we learn that Bootsie is dead and even his beloved home, the house his father built with his own hands, has burnt down. He has since married for the fourth time and seems more settled. But that was before Hurricane Katrina. The Tinroof Blowdown, which deals with Robicheaux in the aftermath of Katrina, will be published this July. Hearts of all fans are already in their boots.

What is this curse that afflicts every American detective? The answer, actually, is easy: Raymond Chandler. His creation Philip Marlowe had enough feelings, self-doubt, loneliness and cynicism to populate a dozen existentialist novels. He is a philosophical man, with a fierce code of honour which he follows come what may. He is lonely and proud, and a tragic hero, a samurai whose credo is out of place in a world turned corrupt and venal.

Marlowe is the iconic American private eye, and every American crime writer would have read each of the seven novels featuring him many times. In American detective fiction, Marlowe is the act to beat. The plot is hardly the benchmark here; it?s the man. In his seminal essay The Simple Art of Murder, Chandler defined his idea of what the American private eye should be: ?But down these mean streets a man must go who is not himself mean, who is neither tarnished nor afraid?He must be a complete man and a common man and yet an unusual man. He must be, to use a rather weathered phrase, a man of honour, by instinct, by inevitability, without thought of it, and certainly without saying it?He will take no man?s money dishonestly and no man?s insolence without a due and dispassionate revenge. He is a lonely man and his pride is that you will treat him as a proud man or be very sorry you ever saw him.? Very high standards indeed. Marlowe met them, and everyone since has been struggling to keep up.

And every American crime writer also knows that after he marries at the end of The Long Goodbye, Philip Marlowe, now happy and settled, turns into a softer and decidedly less attractive person in the next-and last-novel Chandler wrote, Playback. So personal grief and loneliness will always be the lot of the American gumshoe.