The color, they say, has no obvious role in survival; the genetic machinery simply changed, perhaps for no other reason than that it could. Indeed, in some ancient societies, redheads were burned at the stake, buried alive, or sacrificed to the gods. That redheads survived at all means that we must find them sexier than the other shades.

The gene is said to be recessive, a poor choice of words if ever there was one. A better word is rare. In Scotland, 1 in 10 people are redheads. In Copenhagen, the percentage of those with “strikingly red hair” is 1 in 50. They stand out like torches. In the often boring world of statistics, professors try to explain the phenomenon of “clustering”—the false importance attached to a group of unrelated events. Inevitably they use as an example the scenario of not having seen a single redhead for weeks, only to walk down the street and run into four or five in a few minutes. What would we call this—luck?

Historians note that the newly arrived redheads became the stuff of legend, as warriors, traders, and explorers. Vikings spread the genetic magic that is red hair to distant cultures across the seas. Redheads are restless, marked by incredible energy—what today is called hyperactivity. In the 1980s, a psychologist announced that redheaded children were three to four times more likely to ricochet around a classroom or lab. These children, he said, shared such qualities as “overexcitability, short attention span, quick feelings of frustration, and usually, excessive aggressiveness.” Not our choice of words. Consider, what is the opposite of overexcitable: inert? Would you want to date someone like that?

Redheads are meant to run free. They resist oblivion. According to doctors, redheads are harder to knock out before surgery than blondes or brunettes. The trait can be measured, in that redheads require 20 percent more anesthesia.

Clara Bow, the “It” girl of the 1920s, was a redhead. Her crown and the title of her breakthrough film were based on a novel by Elinor Glyn. The author of an article in Cosmopolitan, trying to make sense of Freud’s theory of sex, the libido, and this slippery new concept of sex appeal, finally gave up, saying that some people had “It”—and that’s all there was to it. Film reviews of Clara Bow—the blueprint for all other flappers—sprouted adjectives. She was plucky, unfettered, ever resourceful, naturally vivacious, cunning, sensuous, radiant, and carefree, a woman with irresistible charm and a “genuine spark of the divine fire.” In other words, a redhead. Indeed, Red Hair was the title of one of her features, along with Dangerous Curves, Hula,and Rough House Rosie.

In subsequent years, other redheads refined the spectrum. Katharine Hepburn could stand toe to toe with Spencer Tracy or Humphrey Bogart, sparks flying. Maureen O’Sullivan was Jane to Johnny Weissmuller’s Tarzan, a vision of natural vitality whether swinging from vines, swimming naked, or strolling about in a remarkably short jungle wrap. Bette Davis could play the temptress Jezebel or, conversely, the female lead in Satan Met a Lady. Deborah Kerr rolled in the surf on the beaches of Hawaii with Burt Lancaster in From Here to Eternity and was the one with hair in The King and I. These redheads certainly had It, and it blazed forth, even in a world of black-and-white films. Those not lucky enough to see them in person picked up visual clues in the posters and cards that lined the lobbies of movie palaces across the land, images lovingly hand-colored by anonymous theater owners, adoring fans (and other redheads) who wanted the world to get It right. Was it a love for redheads that made Ted Turner want to colorize the classic movies of the past?

During World War II, Rita Hayworth was one of our most popular pinups, her image carried in pockets and in footlockers and taped to ship bulkheads by boys far from home. In the 1946 movie Gilda, she gave the ground rules for being a redhead: “If I’d been a ranch,” she said, “they would have named me the Bar Nothing.”

With Technicolor, redheads came into their own. The world learned to appreciate the varietals, the shades of temperament displayed by the group—from the perpetual motion of Ann-Margret, to the vulnerable toughness of Molly Ringwald, the provocative nonchalance of Susan Sarandon, and the sultry simmer of Nicole Kidman.

With redheads, rules don’t apply. They make their own way and, in doing so, change the world. Margaret Sanger, the radical who championed birth control, was a redhead. Lucille Ball pioneered the television sitcom—and, as it happens, the longest string of reruns in history. Bonnie Raitt showed that white girls with red hair could sing the blues (and play slide guitar) in a way that would make grown men bleed.

According to the Redhead Encyclopedia, there has never been a saint with red hair.

Redheads demand to be taken seriously. One reporter counted more than 500,000 Internet sites devoted to blonde jokes, compared with 1,300 for brunettes and 44 for redheads. Most of this last group, he wrote, are actually jokes about blondes. Who would risk a redhead’s ire? Remember Lizzie Borden? A redhead.

An Internet dream dictionary explains the allure of red this way: “Dreaming you are a redhead suggests you need more spontaneity and vitality in your life. Make some dramatic changes.”

And women are increasingly paying attention to their dreams. When Playboy first started photographing women, perhaps 7 percent of the female population colored their hair. Most were matrons seeking to preserve their original shade. Today, more than three-quarters of American women play with hair color—and 30 percent choose shades of strawberry and auburn. The palette includes tints such as Sedona Sunset, Peruvian Fire, Caribbean Mahogany, and Spiced Tea. It must drive the statistics professor crazy.

The redheads captured here appeared in the magazine in the fifties, sixties, and seventies. Some were famous, some simply the girl next door. In all probability, they are the real thing. What do you notice first? Their hair? Their eyes? Their delicious, creamy skin? (One editor remarked that redheads are the only women who come with a built-in sex manual. Think freckles. Think Connect the Dots.)

When Playboy decided that the color needed its own celebration, the unsung copywriter for “Reds” rhapsodized: “Redheads are like other women—only more so. The first thing you notice is a soft fire around their faces—an auburn halo that vibrates in high gear. A kind of heat that has nothing to do with temperature radiates from them like a visual perfume, a curious, insistent allure. By a happy coincidence of pigment and spark, redheads improve the world around them.”

Yes.