"Traditionally, two earmarks of adolescence are the beliefs that time is limitless and choices are unnecessary," says Dr. Ava Siegler, a psychotherapist who specializes in adolescent psychology. "Many singles in their thirties have adopted that same attitude. In the past, there were certain developmental tasks, like marriage and child-rearing, that signaled one's adulthood. But in today's urban culture, it's acceptable to postpone those tasks for as long as possible."

In addition, because of the skyrocketing cost of housing, particularly in Manhattan, more and more young people are moving back in with their parents, further prolonging adolescence. Since 1970, the number of adult children living at home has increased 85 percent.

Today's singles find themselves in a difficult cultural bind. While they're less mature than their parents in many ways, they're also far more sophisticated. "The seventies bombarded us with information," says Schwartz. "We learned about our psyches, our sexuality, and our bodies. Consequently, our level of expectation has changed, and we're looking for more in a partner than ever before."

A 35-year-old editor at a women's magazine says that she wants an "evolved" man—someone who is strong and assertive, yet vulnerable and supportive. She recently began dating a man she likes very much, but she worries that he is not "emotionally articulate." "I've been in individual therapy for eight years and in group therapy for six years," she says. "I've learned a lot about opening up. He's totally closed, and it scares me. We've only gone out three times, but I don't think it's going to work out."

"Women have always had an easier time expressing themselves emotionally," says Dr. Herbert Zerof, author of Finding Intimacy and director of the Dilworth Family Therapy and Psychiatric Group in Charlotte, North Carolina. "Basically, most males are duds on the issue, and while there's nothing wrong with the concept of an evolved man, there may not be a lot of men who fit the bill. What's important is an evolved relationship. But people focus on someone's weaknesses instead of his strengths. Everybody has to settle to some degree."

ME FIRST: "Marriage requires self-sacrifice," says one sociologist. "But that concept was alien to the baby-boom generation." They feel that marriage destroys freedom and self-expression.

Donna Kaplan, who works as an administrative assistant, has lived alone for eighteen years. But, at 38, she would gladly trade her freedom. On the wall in her Upper East Side studio is a photograph of her mother in a wedding gown. "She was a beautiful bride," Kaplan says, with a hint of sadness. Although Kaplan is very attractive, with long brown hair and high cheekbones, she has never had a long-term relationship. "When I was in my twenties, I picked unobtainable men," she says. "I guess I was asking for trouble. Now I just want a guy who is moderately successful. He should be okay-looking, but he doesn't have to be Robert Redford—just a nice, down-to-earth, average human being."

Lately, Kaplan has been attending "singles parties," for which she pays a fee in advance. She says she doesn't know what else to do. "When I was younger, I used to take a share in a house on Fire Island," she explains. "Usually it was a zoo, and I never met anybody I liked. But what's really depressing is now when I go to these singles parties I see the same old faces from Fire Island. Ten years later, everything is still the same—except the guys are balder and more obnoxious."

Kaplan says the worst thing about being single is the "unbearable loneliness." She would like to have a child, but realizes that the possibility is becoming remote. "At times, I feel very old, and it makes me sad to realize that in a year or two, the choice will be out of my hands." Kaplan feels increasingly powerless about her situation. She beats her body into shape nightly at the New York Health & Racquet Club, although she knows a toned figure may not be enough. "I've gone out with 55-year-old guys who tell me I'm too old," she says. "Every day I see these young beautiful girls, and I realize a 'mature' 38-year-old doesn't stand a chance."

Kaplan's plight is not uncommon. Society's double standard on aging, plus the demographics of the baby boom, has placed women at a real disadvantage: Men a few years older than the baby-boom women are in short supply. The ratio becomes even more unfavorable as a woman gets older. There are 30 percent more available women than men in their thirties, according to the Princeton University Office of Population Research.

Single men enjoy a privileged position. They can choose a woman their own age, or they can select someone much younger. While divorce recirculates available men, statistics show that men in their forties frequently remarry women who are ten years their junior. Such conditions have led to what Siegler calls the spoiled-boy phenomenon. "When there is a surplus of women," she says, "men tend to avoid commitment, because they feel the world is their oyster. No demands are too high."