SOMETHING ABOUT Mary E. Cunningham is even more striking than the cascading blonde hair that entranced media photographers during her recent moment of newsworthiness. Cunningham's background closely resembles those o' many of Radcliffe's aspiring career women. Known as a superachiever in high school and college, Cunningham graduated with honors from the Business School--where a dean predicted that within a decade she would be the first female chief executive of a Fortune 500 corporation. Cunningham, unlike the corporate establishment, saw no contradiction between being attractive and being a competent professional. "I always wanted to be a role model for other women," Cunningham told reporter Gail Sheehy last week.

In a sense, Cunningham has become a role model--not for the path successful women might pursue, but instead for the treatment women in business can expect. For three weeks one of the leading female executives in the nation, Cunningham resigned as a Bendix Corporation vice president because innuendoes that her "meteoric" rise had benefited from a close personal relationship with Bendix's chairman made it impossible for her to remain. Meanwhile, William Agee, the chairman--and the man responsible for the promotion decision under fire--has suffered embarrassment but remains secure in his post.

Cunningham's predicament outlines just how vulnerable women are in male-dominated corporate hierarchies. What happened to Cunningham could happen to any young woman who rises too far, too rapidly in the eyes of her male colleagues. "What this means," a woman student at the Business School said yesterday, "is that all corporate women are going to have to put up the barricade and watch their defenses constantly."

As soon as the rumors became public, the issue of Cunningham's integrity dominated coffee table chatter and cocktail party scuttlebutt at corporate gatherings everywhere. The press lavished so much attention on speculations about Cunningham's morality that The New York Times--after running the story on its own front page--editorialized, "Never in recent memory has so much been written about so little," The question both the media and the business world seemed to want answered was not whether Cunningham was qualified, but the snickering, "was she or wasn't she?"

Cunningham's appointment as vice president for strategic planning had been confirmed by Bendix's directors, who further showed their support by denying her request for a leave of absence when the rumors began. Despite that, observers within and outsidv the corporation jumped to the conclusion that Cunningham must have used sexual favors to reach the top. Although a man a year younger than Cunningham had been appointed without incident to a top-level post the year before, as a women, Cunningham's youth automatically made her suspect. The most retrograde lesson yet drawn from the affair comes from a Business School professor, writing in the Wall Street Journal, who cautions corporate executives to be careful abut promoting women quickly merely because of the suspicious that inevitably arise.

Perhaps Cunningham had muddied the waters by appoaring with Agee at quasi-social events (like the Republican National Convention) and by speaking of him in terms like, "He is the finest human being I've ever met." And Agee certainly made matter worse by trying to dispel the gossip in front of a public meeting of 600 employees. Both Agee and Cunningham have acknowledged their relationship as mentor and protege. In business, that type of relationship is not only customary, but often promoted at business schools as the key to success. And women, precisely because they have not yet been fully accepted in the corporate world, most need such mentors. Yet they must unwittingly call their own integrity into question if they develop close professional relationships with their bosses.

Different studies have proved personal compatibility and not strict job performance to be the most important reason for most corporate promotions. The system may be rotten, but men use it regularly--on the golf courses and tennis courts, at cocktail parties, and within their circles of family and friends. When women use such tactics, their qualifications are questioned; when men use them they are just winked at. The selective application of this ethic becomes a screen to keep women from climbing corporate ladders.

There are men who argue that sexual favors are a distinct and unfair advantage for women in corporate competition. Yet when sex enters business decisions, it far more frequently works against the woman who is harassed by a superior and forced to compromise herself or lose out in the promotional game. And, as Ellen Goodman points out in the Boston Globe, if women actually had this unfair advantage and used it, far more would have reached top corporate positions by now.

The Mary Cunningham incident does not reveal any startling new truths, only that old assumptions take along time to die. If anything, the episode shows just how urgent is the need for a stronger affirmative action effort at the highest corporate levels. Nowadays, any woman who reached a position like Cunningham's--after all, only one of 11 vice presidents in the nation's 88th largest corporation--is viewed as an oddity whose personal behavior needs to be scrutinized to explain her unusual success. Only when the number of women in the boardroom roughly equals that of men will Mary Cunningham's accomplishments--and not her blonde hair--be the focal point of debate.