Back in his high school years, Ralph Keyes fell for a girl who happened to be 3 1/2 inches taller than he. Despite the height difference, the friendship blossomed until the night he took her to a school hop.

During the fast dances, Keyes recalls, "Everything was fine." The trouble came during the slow dances. While his classmates snuggled cheek-to-cheek, for Keyes and his date "it was cheek to chest."

That "was the ballgame" for that romance, says Keyes. "I couldn't handle it."

Being short can be frustrating, says Keyes, who has written a book about the effect height has on our lives. For one thing, talls and shorts see the world differently:

"Talls note whether we've dusted our refrigerator top; smalls know when we've spilled soup on our tie."

As a child, Keyes dreamed of growing to at least 6 feet 6 inches, but now at 35 he is fairly reconciled with his -- to be precise -- 5-foot-7.62-inch frame.

Still, he "takes it as a compliment" when someone says he is taller than they expected.

Not everyone would consider Keyes (rhymes with eyes) short, though he doesn't reach the national average for men: 5 feet 9 inches. (For women, 5 feet 3.6.) Last year he was the keynote speaker at a University of Texas medical school symposium on the experience of being short. "In the first row," their arms folded "impassively, " sat an "unimpressed line of dwarfs and midgets."

"Some of you might think it presumptuous of me to be here," he told the group, explaining, however, "I'm just short enough to sense that smaller people get treated differently."

For Keyes, who teaches writing at Temple University in Philadelphia, shortness is both "serious" and "absurd" -- he did a piece on "Runt's Lib" for Playboy a few years ago.

Being short, for one thing, may cost you money on the job. Studies indicate, he says, that tall people on the average get paid more than short. This may be because tall people better fit the image of a corporate leader.

In what he calls the "angry" chapter of his book, "The Height of Your Life" (Little Brown, 331 pages, $11.95), Keyes observes that "American games are geared to talls." A football or basketball player in the mid-6-foot range "doesn't have to be terribly talented . . . but players in the mid-5-foot range must be brilliant to succeed."

He recalls the time he tried to tackle a 6-footer in a school scrimmage."I grabbed him around the leg, but he just kept dragging me for 20 more feet."

The growing popularity of soccer in schools, he suggests, may be because it doesn't favor either talls or shorts. "If such trends continue -- if our historic preference for sports that favor smalls, or, better yet, favor no size in particular -- people of all heights will come out winners."

Shorts also must put up with "hideous nicknames" in school: "runt," "pipsqueak" and "shrimp" among them. Something of the sort may continue the rest of their lives. Short men, says Keyes, get described in the media as "feisty." It's the talls who are "distinguished." Short women are "cute" or "perky," never "elegant."

Only this week, Time magazine describes Al Neuharth, chairman of the Gannett newspaper chain, as a "wiry (5 ft. 7 in., 150 lbs.)imp." Imp or not, Neuharth, pulling down a $1 million-plus yearly income, proves talls don't get all the big bucks.

Keyes, whose wife is 5 feet 4, thinks a short person can do little more than "laugh" or "make a joke when someone takes a potshot at his or her size, though he doesn't consider it "a laughing matter." Otherwise, "you're a poor sport."

As for the absurd, Hollywood often has gone to extremes to conceal the heights of its stars. In "Casablanca's" final, tear-jerking airport scene, Keyes reports, Ingrid Bergman had to walk in a specially-dug trench to keep from towering over co-star Humphrey Bogart. i

Once Alan Ladd, at about 5 feet 4, was mismatched in "Boy on a Dolphin" with a 4-inch-taller Sophia Loren. He stood on crates. Ladd is reported to have compared working with Loren -- from where he stood -- to "being bombarded with watermelons."

Keyes thinks Jimmy Carter, like many public figures, may be fudging on his reported height for political reasons, since, according to Keyes' research, the public generally attributes "leadership" qualities to tall people.

Keyes challenged the president (whom the White House press office says is 5 feet 10 inches) to stand barefoot back-to-back with him at the Lincoln Memorial at noon Tuesday to determine who is the tallest. Carter didn't show, and Keyes kept his shoes on.

When talking about height, says Keyes, "people are usually very generous to themselves. They fudge upwards, and that becomes their height forever more."

Our love affair with height begins, he believes, "when we are lying in a crib looking up at those literally towering bodies -- with all that power."

It's reinforced in childhood, when parents or other adults enthuse over a child's growth and warn that they won't grow up if they don't eat all their spinich. And, he adds pointedly, "big kids could beat you up" or you're left out "when teams are chosen up."

Says Keyes, "It's hard to miss all the rewards given to taller bodies."

Initially, he wanted to grow tall, because "bigger people are intimidating. I wanted the respect that taller bodies get." But as he grew older, "I got less interested in being intimitating."

One of the "payoffs" of writing his book, he says, "is realizing the advantages of my size."

One study, he found, suggests that while men turn to tall people for leadership, they want a shorter man for a friend. "At this point, I'd rather have a friend."

Smalls tend to have less back problems, reports Keyes. They have better balance, making them less likely to slip and fall. They need less food -- "In times of famine, taller bodies are the first to go."

In sports, smalls "have the advantage when endurance is rewarded," such as marathon racing.

They fit "comfortably into all kinds of cars"; they have "a neat and tidy quality."

And, adds Keyes, there's one more advantage. "As a kid, I could climb higher and further out on a branch." Big and Small in the Public Eye

The following, says author Ralph Keyes, are "people in the public eye who regularly fool it": Smaller than you might imagine: Marlon Brando Charles Bronson Johnny Carson Geraldine Chaplin Julie Christie Robert Conrad Walter Cronkite Bette Davis Robert De Niro Kirk Douglas Peter Falk Jane Fonda Buckminster Fuller Steve Garvey Patty Hearst Katharine Hepburn Reggie Jackson Mick Jagger Paul Newman Jack Nicholson Laurence Olivier Burt Reynolds Suzanne Somers Sylvester Stallone Ringo Starr Elizbeth Taylor Andy Warhol Raquel Welch Henry Winkler Taller than you might imagine: Warren Beatty Ingrid Bergman H. Rap Brown Fidel Castro Howard Cosell Jules Feiffer Bobby Fischer David Frost Jerry Lewis Billy Martin Richard Nixon Gilda Radner Ronald Reagan Cybill Shepherd Tom Snyder Lowell Weicker Either way: James Caan Farrah Fawcett Joe Garagiola Hugh Hefner