When constant complaining about a few unbearable customers was dragging down morale at a Pennsylvania bank, the president called in a management humor consultant who recommended he initiate a "Worst Customer of the Week Award," to be presented -- along with a bottle of champagne -- to the employe with the best Friday afternoon tale of woe.

"Humor changed their perception of the situation," says David Baum, the Philadelphia consultant who turned dread into drollery at the Doylestown bank. "Tellers were soon calling the worst customers over to their windows in hopes of winning the champagne. The customers felt some positive attention and stopped being such pains."

Balancing gravity and levity in the workplace is hardly funny business.

While lip service has long been paid to a sense of humor at work, traditionally the closer you got to the bottom line -- money -- the fewer laughs you heard.

Today, however, personnel officers and executive headhunters may mark "sense of humor" as a major plus on job applications. Ads in business magazines promote products such as executive joke newsletters and the "Instant Card File of Humor -- 1,400 sparkling laughmakers filed on 4x6 cards in 97 subjects" for $19.95. And social scientists who 15 years ago would have jeopardized their academic credibility by investigating humor are now making careers of researching wit and whimsy.

"Appropriate use of humor in the workplace enhances communication, motivation, creativity and ultimately productivity," says Baum, 30, who, besides consulting businesses and organizations on humor, doubles as coordinator of training and development at Philadelphia's Thomas Jefferson University.

Based on his five-month study of humorous interaction at Shared Medical Systems, a 1,200-employe computer firm on the outskirts of Philadelphia, Baum stresses that humor is a powerful tool that can provide a competitive edge in climbing the corporate ladder.

According to a recent survey sponsored by Robert Half International, corporate America thinks business is best when it isn't strictly business. The executive recruitment franchise firm headquartered in New York asked executive vice presidents and personnel directors of 100 of the nation's largest corporations: "Do people with a sense of humor do better, the same, or worse at their job than those people who have little or no sense of humor?"

Eighty four percent of the execs replied employes with a sense of humor did a better job. more creative, less rigid and more willing to consider and embrace new ideas and methods," says Robert Half, warning that in the long run, the joke will be on companies that frown on badinage.

While Henny Youngman has yet to leave his mark on most boardrooms, changes in the American workplace, say social scientists, are gradually changing the profile of the prize employe of the '80s -- independent, autonomous and creative, someone who tends to work hard, play hard and laugh hard. CEOs increasingly ask the manager with a sense of humor, "Take the initiative . . . please." But experts warn not to turn in your pin-stripes for a clown costume. As always, a good punch line depends on good timing.

"Humor is one of the prime social adaptive mechanisms that we have," says John Parrish Sprowl, a University of Connecticut professor of communications science who has been conducting research into what is funny.

Work, says Sprowl, provides common ground for congeniality. "In the workplace," he says, "there is a special need to gain cohesiveness with people you maybe wouldn't have chosen to be with in other situations.

"For people to be colleagues, they need to converse in certain ways and find some of the same things funny. We develop in-group humor at work. Funny spontaneous situations and do-you-remember-the-time-when stories make up a lot of humor at work and bind people together. Jokes and humor are a sign of a well-formed group, and a lack of them is a problem."

Sprowl adds that while many of us know intuitively the best uses for humor in social interaction, its effective application in workplace alliances is a new science to management: "We make people less nervous with humor, we make situations more 'cope-able' with humor, we make people feel included with humor -- most effective managers know how to do that."

Besides a rapport builder, humor is a valuable device in defusing workplace tension.

"It's a key way of working out a conflict that couldn't otherwise be worked out," says Howard R. Pollio, professor of psychology at the University of Tennessee, Knoxville, who has observed the interplay of horseplay in work groups from longshoremen to college professors. "It lets you, for a moment, transcend the constraints and boundaries of a situation."

David Baum recalls the time the government of Northern Ireland hired him to try to find a humorous common ground during the height of Catholic-Protestant tensions. On his first night in Belfast, he was taken to a pub where talk usually avoided the topic of religious strife. But a drunk who overheard Baum's American accent staggered over to him.

"Tell me, now, what d'ya think of our troubles here?"

The pub crowd immediately was hushed and edgy. Baum was scared. The Irishman repeated his challenge.

"I said, Yank, tell me what d'ya think?"

Baum slowly climbed off the stool and unbuttoned his coat, and the drunk began to roll up his sleeves. Suddenly the crowd exploded in laughter.

The front of Baum's T-shirt read: Don't Shoot -- I'm Jewish.

"A lot of humor in the workplace is of a negative nature," says Baum, "because a lot of communication in the workplace is of a negative nature." Researchers say that is especially true of the humor that travels up and down the organizational hierarchy of a worksite.

"In the spontaneous ebb and flow of conversation or activity, people do and say humorous things," says Pollio.

"And many of those humorous things have specific targets. Someone will target another person, one barber will target another barber, an editor will target a particular reporter. The more closely knit and the more comfortable the people are, the more they target people directly.

"What clearly happens is targeting indicates a reaffirmation of their bonds. The intimacy of a group can be evaluated by the amount of targeting they do of each other. And them that gives a lot gets a lot."

The friendly workplace zing, however, carries with it a hidden agenda. If a manager or upper-status person wants to "reduce the hierarchy" -- in effect, impose momentary equity, says Pollio -- the humor will be self-deprecating.

"If there is no attempt to change the hierarchy," he adds, "the pattern of targeting will directly reflect the hierarchy. Humor will be used to maintain it and will always be directed downward. In court, for instance, the judge is the only one who tells a joke and the judge is the only one who ever gets the big yuks. The lawyers will always laugh. That hierarchy isn't open to change."

In other words, say researchers, the sound of one man's laughter -- that of the corporate leader or top executive -- often establishes the humor parameters of a workplace.

For instance, when the president of a Washington publishing firm decided to deluge his staff with memos (re: company rules and staff reminders), a senior executive thought a parody would change staff groaning to healthy guffaws. He created a fake memo warning staffers of the dangers of "memo-itis, a corporate sickness whose main symptom is mental incontinence." The only cure: Do time in a "memo re-education camp."

Staffers loved it. But red-faced with rage, the company president, with crumpled evidence in hand, marched into the senior exec's office, slammed the door and barked, "I don't think this is the least bit funny."

Knowing how and when to use humor is a calculated risk in the workplace, and it can backfire, says Sprowl. The senior executive's bogus memo, he explains, is an example of humor for an appropriate purpose -- to help cope with an unbearable situation -- until the leader said it was inappropriate.

Topics and timing prove critical. A ribald joke at the expense of your boss, for instance, could prove disastrous if your boss is within earshot, but unifying among your colleagues if the top dog is out to lunch. "Most people would find humor at a funeral inappropriate," says Sprowl, "and at a board meeting when important policy issues are being discussed, people aren't anxious to hear a joke either."

Richard A. Cosier, chairman of the department of management at Indiana University School of Business, says, "Too little humor and your contributions would be much less than they could be. Too much of it and you've got problems with the career and organization. Where that middle range lies depends on a lot of things -- the nature of the organization, the kind of job it is, what the boss is like. The organizational culture is the key to what level of humor is appropriate. Some organizations we've looked at are so tight, mechanistic, formal and conservative that if you were humorous you'd be looked at as off-the-wall and superficial."

Sprowl cautions, "That harms a person's career development. If people use humor inappropriately, it damages professional credibility" -- and that's no laughing matter.