THE POSTPONED GENERATION; Why America's Grown-Up Kids Are Growing Up Later. By Susan Littwin. Morrow. 252 pp. 16.95.

SUSAN LITTWIN'S subject is that generation of young Americans, most of them in their twenties, who are middle-class, college-educated, privileged beyond the imagination of any previous generation -- and almost totally unequipped to face the realities of adult life in a society and economy that have changed significantly since their expectations were formed. They are, in effect, the children of the '60s; many of them were born in that tumultuous, disruptive decade, and they were raised in an atmosphere that combined "a consumer culture that worshipped youth" with an alternative culture that assumed "a right to self-fulfillment, choice, power, even the right to transcend ordinary life." By and large they are decent people, more comfortable with a genuinely egalitarian society than any previous generation; but they also believe, as their parents and teachers encouraged them to, that they are "special," that as a matter of entitlement they are owed not merely a living but a rich, fulfilling and rewarding one.

It is a formula for disaster, especially in the '80s, in which reality is "very different and much more unpleasant" than it was in the '60s. People who as children were raised to believe that the world was going to be delivered to them in a handbasket -- "They taught us to be happy," one says. "To grow. A career doesn't matter" -- are now discovering as young adults that the real world is something else altogether. It is a place where there are twice as many college graduates as college-level jobs; where college-educated women are entering the job market rather than keeping house; where job opportunities are ample for engineers and computer specialists but in short supply for liberal-arts majors, "who expected that society would value them just as much as their teachers did."

The result is that as they leave college and come into the job market, many of these young people undergo what sociologists call "downward mobility": they learn not merely that life will not offer them as much as they had expected, but that they "will not have the income or the status that their parents had." Littwin discusses two of them, whom she calls Alexa and Eric. "Everyone lowers their goals after graduation," Eric tells her. "It's devastating to the ego. You're not on top of the mountain anymore." To which Littwin replies:

"I don't know who told them they were on top of the mountain, but it seems to be implied in the contract his generation has with life. He and Alexa grew up almost two thousand miles away from each other and perhaps light years away in background. Yet the same themes appear in both stories, like a refrain. Both chose career-oriented majors and assumed that success came with the degree. They chose their fields rather casually. They hate the thought of relocating. And they set great store by having a stylish place to live. This is not a generation of pioneers. They are just kids with a high sense of entitlement and a not so high sense of reality."

THEY ARE ALSO people who, having passed through four years of higher education, are remarkably uneducated. Littwin quotes a report by the National Commission on Excellence in Education: "Each generation of Americans has outstripped its parents in education, in literacy and in economic attainment. For the first time in the history of our country, the educational skills of one generation will not surpass, will not equal, will not even approach, those of their parents." For too many members of this generation college is remedial, rather than higher, education; the plain if cruel explanation is that too many members of this generation are in college not because they are prepared for it but because our society has presented it to them as an entitlement. A man who has spent three decades in close contact with college students describes current ones as follows:

"They don't read. They don't even read newspapers except for sports and comics. They are abysmally ignorant of world figures. Mention Albert Schweitzer or Bertrand Russell, and they say, 'I didn't take the course.' The talk here is disappointing because they never talk about anything outside of their immediate ken. They have no common core of civilized knowledge to draw on. Their conversation is utterly devoid of intellectual curiosity or concern about social problems. They talk only of sports and television, with a little personal gossip. Their knowledge of popular television is astounding. . . . They even refer to themselves as kids. The coaches refer to these huge Neanderthal hulks as kids. We would have killed anyone who called us kids when I was in medical school in Scotland. At twenty-two, I had the power to sign someone into an asylum. When do they assume responsibility?"

That's the central question, and the answer is not encouraging -- for the young people themselves, for their parents, or for the society in which sooner or later they will take their place. Rather than confront adult life's hard responsibilities and realities head- on, many members of this generation are avoiding them. Some do so by staying in college long past the fulfillment of their obligations for a degree; some drift on into graduate or professional schools; others wander in and out of jobs they regard as beneath themselves, refusing to make entry-level commitments to specific careers. "Commitment," as Littwin correctly observes, "requires that you choose one thing and give up something else" -- a choice that too many young people avoid through one ruse or another, thus, in effect, avoiding adulthood.

So they remain adolescents, in spirit if not in fact: "The twenty-two-year-old, and even the thirty-year-old, continues living in his parents' home or in some other, more subtle way remains a child, financially and emotionally dependent." Littwin argues that, except for those college graduates who move into rewarding jobs in the booming field of high tech, "it now takes another decade to grow up in our culture"; people who a generation earlier would have entered adult life upon leaving college now may not do so until their 30th birthdays have passed. They simply tread water, floating along in a Micawberesque self-delusion that something will turn up.

Somewhat surprisingly, considering the toughness of her analysis of this "postponed" generation, Littwin in the end capitulates to it. Her advice to parents is "simply to let go, to accept that adulthood happens a decade later," and she expresses the hope that people who "have had time to think, explore, experiment" will arrive at their belated adulthood "knowing who they are, and they won't have mid-life crises." But neither the advice nor the prognostication seems especially sound. Though she is right in saying that parents cannot nag their children into adulthood, it does young people no good if their parents subsidize their indolence and indecision; neither is there any particular cause to be optimistic about the long-term prospects of people who are deficient in education and self-understanding but oversupplied with complacency and expectation.

It is too bad that Littwin ends her book on so apologetic a note, for up to that point it is a careful, thorough and revealing piece of work. Her prose grinds along rather mechanically and her taste for the language of pop psychology is lamentable, but she has done her homework well and from it she has drawn conclusions that, however depressing, are inescapable. Appealing, likeable and good-hearted though so many of these young people are, they are living in never-never land: preoccupied with themselves, expecting instant gratification of their desires, blissfully unaware of the real value of money or the labor that produces it. They are in for a great fall; when it comes they -- and the rest of us as well -- will be badly hurt.