An entire approach to writing was, for quite a long while, labeled with a compound word that was ungrammatical, condescending, and ultimately, damaging.
The "whodunnit" was a product of what is often called the "golden age" of mysteries, the period that can be said (although probably not very accurately) to have begun in both England and America in 1920-21 with the publication of Agatha Christie's first novel, The Mysterious Affair at Styles. The book set a whole slew of parameters for much of what was to follow: country houses, a closed world which only a small number of people could enter or leave, an aristocratic victim and suspects, a classless detective, exotic murder weapons, and a welter of motives, suspicious actions, creaking stairs, and the rich, ripe smell of red herrings.
Raymond Chandler would later characterize this fictional environment as one in which the suspects "sit around sipping Singapore slings and sneering at each other while the flat-feet crawl to and fro under the Persian rugs with their derby hats on."
The problem with the classical mystery was that it really was a whodunnit, and little more. The whodunnit had at its steely little heart not love and longing, but floor plans and timetables, tos and fros, the ticking of the clock. When all was said and done, Lady Furtheringham and the Earl of Fogwart and the racy young Mr. Peffington-Smythe exist only to help the detective penetrate the truth of, as Chandler says, "bits of charred paper and who trampled the jolly old flowering arbutus under the library window." As characters, the people in most of these books are cogs and wheels, and the mystery itself is a machine. Human motive and individual behavior are oil and gears. The whole thing is a bit like one of the elaborate cuckoo clocks in which a surprising panorama of simulacra parade by, doing the same things over and over. The books are puzzles, no more and no less.
And they sold in the billions, and, yes, that's billions with a "B." Christie's sales alone account for approximately four billion books. So when we look back and get the impression that the golden age had the stage to itself for a long time, it's easy not to see, beneath the avalanche of secretive butlers, shady vicars, and curare darts, that Dashiell Hammett published Red Harvest in 1929, only eight years after the English publication of The Mysterious Affair at Styles, and followed it up only a year later with The Maltese Falcon.
Red Harvest was a game changer, the modern world arriving on a bolt of lightning. Hammett, as Chandler says, "gave murder back to the kind of people who commit it." In doing this, Hammett paved the way for Chandler himself, and with him, for a whole new kind of writing. It looked directly at dark impulse and dark sex, at people with no money and no power, at neighborhoods that most literature of the time drove through quickly, with the windows rolled up. This world was--unlike Colonel Mustard in the conservatory with a fifth-century Greek curling-iron--real, at least in the hands of good writers.
Some people could tell the difference. There was Chandler, of course, and in 1945 the lion of the day's literary critics, Edmund Wilson, wrote a famous New Yorker piece, "Who Cares Who Killed Roger Ackroyd?" eviscerating one of Christie's most famous books and, by extension, the entire genre.
Today we live in a new golden age in which the heirs of Hammett and Chandler can explore virtually any aspect of human life, and set it anywhere in the world. Some of the best writing of our age is being done by writers working in what's usually called "crime fiction," in which, broadly speaking, a crisis caused by crime brings character to the fore, revealing unexpected strengths, weaknesses, and moral codes and exploring the mysteries of life, death, and the often rocky interval between. It has become one of the world's great literary forms.
Unfortunately, "crime fiction" is looked down upon as a sort of literary ghetto by the loftier critics, writers, and editors engaged in what they think of as "literary fiction." These labels, of course, are mostly shelving devices aimed at helping bookstores and libraries decide where to put things, but there's an implied hierarchy, too.
And I blame the term "whodunnit" in large part for that hierarchy. The idea that there's something mechanical, formulaic, and two-dimensional about crime fiction persists -- especially among those who can't be bothered to read it. And you know what? Too bad for them. Think what they're missing.