THIS year marks the 40th anniversary of Sloan Wilson's bestseller ''The Man in the Gray Flannel Suit,'' a novel whose title neatly described the corporate dress code of the 1950s. Yet if Wilson were writing today, he might need to rename his book ''The Man in the Cotton Twill Slacks.''
That's the conclusion a culture-watcher could draw after IBM announced last week that it was abandoning its longstanding formal dress code. Goodbye somber blue suits, crisp white shirts, and wingtips. Hello khakis, cardigans, and loafers.
The unstarched look, according to a company spokesman, will make for ''a more collegial work atmosphere.'' It will also test the theory that ''if you're comfortable, you can think better.''
Already, a quarter of American businesses allow a dress-down day on Fridays. Now, with IBM leading the way to all-week sartorial freedom, can other corporate giants be far behind?
Call it the end of an era, but don't consider it total progress.
A less rigid approach to business-wear offers advantages, of course. Assembling a serious wardrobe and caring for it takes time and costs money. Already financial analysts report that employees of the '90s would rather spend money on household goods than on clothes. Wide-ranging fashion choices also offer a welcome freedom from tyrannical designers, who can make entire wardrobes obsolete by dictating changes in hemlines and lapels.
But relaxed dress codes also raise questions: In an era of corporate downsizing, is ''downdressing'' a good idea? Supporters of casual business-wear could argue persuasively that when corporate axes fall, managers dismiss the best-dressed and worst-dressed with equal ease. Proponents of regular business attire could make an equally valid case that managers, given a choice between two workers, might subconsciously choose to keep the one who looks more ''professional.''
Then there are the inevitable gender issues. After two decades of hard-won progress, women now account for about 40 percent of middle managers. But given the disparities that still exist in the workplace, is there a danger that a casually dressed woman will be taken less seriously than a casually dressed man? Alas, the possibility exists.