What Is It About 20-Somethings? - Robin Marantz Henig

2010年8月22日 - New York Times

This question pops up everywhere, underlying concerns about "failure to launch" and "boomerang kids." Two new sitcoms feature grown children moving back in with their parents - "$#*! My Dad Says," starring William Shatner as a divorced curmudgeon whose 20-something son can't make it on his own as a blogger, and "Big Lake," in which a financial whiz kid loses his Wall Street job and moves back home to rural Pennsylvania. A cover of The New Yorker last spring picked up on the zeitgeist: a young man hangs up his new Ph.D. in his boyhood bedroom, the cardboard box at his feet signaling his plans to move back home now that he's officially overqualified for a job. In the doorway stand his parents, their expressions a mix of resignation, worry, annoyance and perplexity: how exactly did this happen?

It's happening all over, in all sorts of families, not just young people moving back home but also young people taking longer to reach adulthood overall. It's a development that predates the current economic doldrums, and no one knows yet what the impact will be - on the prospects of the young men and women; on the parents on whom so many of them depend; on society, built on the expectation of an orderly progression in which kids finish school, grow up, start careers, make a family and eventually retire to live on pensions supported by the next crop of kids who finish school, grow up, start careers, make a family and on and on. The traditional cycle seems to have gone off course, as young people remain un tethered to romantic partners or to permanent homes, going back to school for lack of better options, traveling, avoiding commitments, competing ferociously for unpaid internships or temporary (and often grueling) Teach for America jobs, forestalling the beginning of adult life.

The 20s are a black box, and there is a lot of churning in there. One-third of people in their 20s move to a new residence every year. Forty percent move back home with their parents at least once. They go through an average of seven jobs in their 20s, more job changes than in any other stretch. Two-thirds spend at least some time living with a romantic partner without being married. And marriage occurs later than ever. The median age at first marriage in the early 1970s, when the baby boomers were young, was 21 for women and 23 for men; by 2009 it had climbed to 26 for women and 28 for men, five years in a little more than a generation.

We're in the thick of what one sociologist calls "the changing timetable for adulthood." Sociologists traditionally define the "transition to adulthood" as marked by five milestones: completing school, leaving home, becoming financially independent, marrying and having a child. In 1960, 77 percent of women and 65 percent of men had, by the time they reached 30, passed all five milestones. Among 30-year-olds in 2000, according to data from theUnited States Census Bureau, fewer than half of the women and one-third of the men had done so. A Canadian study reported that a typical 30-year-old in 2001 had completed the same number of milestones as a 25-year-old in the early '70s.

The whole idea of milestones, of course, is something of an anachronism; it implies a lockstep march toward adulthood that is rare these days. Kids don't shuffle along in unison on the road to maturity. They slouch toward adulthood at an uneven, highly individual pace. Some never achieve all five milestones, including those who are single or childless by choice, or unable to marry even if they wanted to because they're gay. Others reach the milestones completely out of order, advancing professionally before committing to a monogamous relationship, having children young and marrying later, leaving school to go to work and returning to school long after becoming financially secure.

Even if some traditional milestones are never reached, one thing is clear: Getting to what we would generally call adulthood is happening later than ever. But why? That's the subject of lively debate among policy makers and academics. To some, what we're seeing is a transient epiphenomenon, the byproduct of cultural and economic forces. To others, the longer road to adulthood signifies something deep, durable and maybe better-suited to our neurological hard-wiring. What we're seeing, they insist, is the dawning of a new life stage - a stage that all of us need to adjust to.

JEFFREY JENSEN ARNETT, a psychology professor at Clark University in Worcester, Mass., is leading the movement to view the 20s as a distinct life stage, which he calls "emerging adulthood." He says what is happening now is analogous to what happened a century ago, when social and economic changes helped create adolescence - a stage we take for granted but one that had to be recognized by psychologists, accepted by society and accommodated by institutions that served the young. Similar changes at the turn of the 21st century have laid the groundwork for another new stage, Arnett says, between the age of 18 and the late 20s. Among the cultural changes he points to that have led to "emerging adulthood" are the need for more education to survive in an information-based economy; fewer entry-level jobs even after all that schooling; young people feeling less rush to marry because of the general acceptance of premarital sex, cohabitation and birth control; and young women feeling less rush to have babies given their wide range of career options and their access to assisted reproductive technology if they delay pregnancy beyond their most fertile years.

Just as adolescence has its particular psychological profile, Arnett says, so does emerging adulthood: identity exploration, instability, self-focus, feeling in-between and a rather poetic characteristic he calls "a sense of possibilities." A few of these, especially identity exploration, are part of adolescence too, but they take on new depth and urgency in the 20s. The stakes are higher when people are approaching the age when options tend to close off and lifelong commitments must be made. Arnett calls it "the age 30 deadline."

The issue of whether emerging adulthood is a new stage is being debated most forcefully among scholars, in particular psychologists and sociologists. But its resolution has broader implications. Just look at what happened for teenagers. It took some effort, a century ago, for psychologists to make the case that adolescence was a new developmental stage. Once that happened, social institutions were forced to adapt: education, health care, social services and the law all changed to address the particular needs of 12- to 18-year-olds. An understanding of the developmental profile of adolescence led, for instance, to the creation of junior high schools in the early 1900s, separating seventh and eighth graders from the younger children in what used to be called primary school. And it led to the recognition that teenagers between 14 and 18, even though they were legally minors, were mature enough to make their own choice of legal guardian in the event of their parents' deaths. If emerging adulthood is an analogous stage, analogous changes are in the wings.

But what would it look like to extend some of the special status of adolescents to young people in their 20s? Our uncertainty about this question is reflected in our scattershot approach to markers of adulthood. People can vote at 18, but in some states they don't age out of foster care until 21. They can join the military at 18, but they can't drink until 21. They can drive at 16, but they can't rent a car until 25 without some hefty surcharges. If they are full-time students, the Internal Revenue Service considers them dependents until 24; those without health insurance will soon be able to stay on their parents' plans even if they're not in school until age 26, or up to 30 in some states. Parents have no access to their child's college records if the child is over 18, but parents' income is taken into account when the child applies for financial aid up to age 24. We seem unable to agree when someone is old enough to take on adult responsibilities. But we're pretty sure it's not simply a matter of age.

If society decides to protect these young people or treat them differently from fully grown adults, how can we do this without becoming all the things that grown children resist - controlling, moralizing, paternalistic? Young people spend their lives lumped into age-related clusters - that's the basis of K-12 schooling - but as they move through their 20s, they diverge. Some 25-year-olds are married homeowners with good jobs and a couple of kids; others are still living with their parents and working at transient jobs, or not working at all. Does that mean we extend some of the protections and special status of adolescence to all people in their 20s? To some of them? Which ones? Decisions like this matter, because failing to protect and support vulnerable young people can lead them down the wrong path at a critical moment, the one that can determine all subsequent paths. But overprotecting and oversupporting them can sometimes make matters worse, turning the "changing timetable of adulthood" into a self-fulfilling prophecy.

The more profound question behind the scholarly intrigue is the one that really captivates parents: whether the prolongation of this unsettled time of life is a good thing or a bad thing. With life spans stretching into the ninth decade, is it better for young people to experiment in their 20s before making choices they'll have to live with for more than half a century? Or is adulthood now so malleable, with marriage and employment options constantly being reassessed, that young people would be better off just getting started on something, or else they'll never catch up, consigned to remain always a few steps behind the early bloomers? Is emerging adulthood a rich and varied period for self-discovery, as Arnett says it is? Or is it just another term for self-indulgence?

THE DISCOVERY OF adolescence is generally dated to 1904, with the publication of the massive study "Adolescence," by G. Stanley Hall, a prominent psychologist and first president of the American Psychological Association. Hall attributed the new stage to social changes at the turn of the 20th century. Child-labor laws kept children under 16 out of the work force, and universal education laws kept them in secondary school, thus prolonging the period of dependence - a dependence that allowed them to address psychological tasks they might have ignored when they took on adult roles straight out of childhood. Hall, the first president of Clark University - the same place, interestingly enough, where Arnett now teaches - described adolescence as a time of "storm and stress," filled with emotional upheaval, sorrow and rebelliousness. He cited the "curve of despondency" that "starts at 11, rises steadily and rapidly till 15 . . . then falls steadily till 23," and described other characteristics of adolescence, including an increase in sensation seeking, greater susceptibility to media influences (which in 1904 mostly meant "flash literature" and "penny dreadfuls") and overreliance on peer relationships. Hall's book was flawed, but it marked the beginning of the scientific study of adolescence and helped lead to its eventual acceptance as a distinct stage with its own challenges, behaviors and biological profile.

In the 1990s, Arnett began to suspect that something similar was taking place with young people in their late teens and early 20s. He was teaching human development and family studies at the University of Missouri, studying college-age students, both at the university and in the community around Columbia, Mo. He asked them questions about their lives and their expectations like, "Do you feel you have reached adulthood?"

"I was in my early- to mid-30s myself, and I remember thinking, They're not a thing like me," Arnett told me when we met last spring in Worcester. "I realized that there was something special going on." The young people he spoke to weren't experiencing the upending physical changes that accompany adolescence, but as an age cohort they did seem to have a psychological makeup different from that of people just a little bit younger or a little bit older. This was not how most psychologists were thinking about development at the time, when the eight-stage model of the psychologist Erik Erikson was in vogue. Erikson, one of the first to focus on psychological development past childhood, divided adulthood into three stages - young (roughly ages 20 to 45), middle (about ages 45 to 65) and late (all the rest) - and defined them by the challenges that individuals in a particular stage encounter and must resolve before moving on to the next stage. In young adulthood, according to his model, the primary psychological challenge is "intimacy versus isolation," by which Erikson meant deciding whether to commit to a lifelong intimate relationship and choosing the person to commit to.

But Arnett said "young adulthood" was too broad a term to apply to a 25-year span that included both him and his college students. The 20s are something different from the 30s and 40s, he remembered thinking. And while he agreed that the struggle for intimacy was one task of this period, he said there were other critical tasks as well.

Arnett and I were discussing the evolution of his thinking over lunch at BABA Sushi, a quiet restaurant near his office where he goes so often he knows the sushi chefs by name. He is 53, very tall and wiry, with clipped steel-gray hair and ice-blue eyes, an intense, serious man. He describes himself as a late bloomer, a onetime emerging adult before anyone had given it a name. After graduating from Michigan State University in 1980, he spent two years playing guitar in bars and restaurants and experimented with girlfriends, drugs and general recklessness before going for his doctorate in developmental psychology at the University of Virginia. By 1986 he had his first academic job at Oglethorpe University, a small college in Atlanta. There he met his wife, Lene Jensen, the school's smartest psych major, who stunned Arnett when she came to his office one day in 1989, shortly after she graduated, and asked him out on a date. Jensen earned a doctorate in psychology, too, and she also teaches at Clark. She and Arnett have 10-year-old twins, a boy and a girl.

Arnett spent time at Northwestern University and the University of Chicago before moving to the University of Missouri in 1992, beginning his study of young men and women in the college town of Columbia, gradually broadening his sample to include New Orleans, Los Angeles and San Francisco. He deliberately included working-class young people as well as those who were well off, those who had never gone to college as well as those who were still in school, those who were supporting themselves as well as those whose bills were being paid by their parents. A little more than half of his sample was white, 18 percent African-American, 16 percent Asian-American and 14 percent Latino.

More than 300 interviews and 250 survey responses persuaded Arnett that he was onto something new. This was the era of the Gen X slacker, but Arnett felt that his findings applied beyond one generation. He wrote them up in 2000 in American Psychologist, the first time he laid out his theory of "emerging adulthood." According to Google Scholar, which keeps track of such things, the article has been cited in professional books and journals roughly 1,700 times. This makes it, in the world of academia, practically viral. At the very least, the citations indicate that Arnett had come up with a useful term for describing a particular cohort; at best, that he offered a whole new way of thinking about them.

DURING THE PERIOD he calls emerging adulthood, Arnett says that young men and women are more self-focused than at any other time of life, less certain about the future and yet also more optimistic, no matter what their economic background. This is where the "sense of possibilities" comes in, he says; they have not yet tempered their ideal istic visions of what awaits. "The dreary, dead-end jobs, the bitter divorces, the disappointing and disrespectful children . . . none of them imagine that this is what the future holds for them," he wrote. Ask them if they agree with the statement "I am very sure that someday I will get to where I want to be in life," and 96 percent of them will say yes. But despite elements that are exciting, even exhilarating, about being this age, there is a downside, too: dread, frustration, uncertainty, a sense of not quite understanding the rules of the game. More than positive or negative feelings, what Arnett heard most often was ambivalence - beginning with his finding that 60 percent of his subjects told him they felt like both grown-ups and not-quite-grown-ups.

Some scientists would argue that this ambivalence reflects what is going on in the brain, which is also both grown-up and not-quite-grown-up. Neuroscientists once thought the brain stops growing shortly after puberty, but now they know it keeps maturing well into the 20s. This new understanding comes largely from a longitudinal study of brain development sponsored by the National Institute of Mental Health, which started following nearly 5,000 children at ages 3 to 16 (the average age at enrollment was about 10). The scientists found the children's brains were not fully mature until at least 25. "In retrospect I wouldn't call it shocking, but it was at the time," Jay Giedd, the director of the study, told me. "The only people who got this right were the car-rental companies."

When the N.I.M.H. study began in 1991, Giedd said he and his colleagues expected to stop when the subjects turned 16. "We figured that by 16 their bodies were pretty big physically," he said. But every time the children returned, their brains were found still to be changing. The scientists extended the end date of the study to age 18, then 20, then 22. The subjects' brains were still changing even then. Tellingly, the most significant changes took place in the prefrontal cortex and cerebellum, the regions involved in emotional control and higher-order cognitive function.

As the brain matures, one thing that happens is the pruning of the synapses. Synaptic pruning does not occur willy-nilly; it depends largely on how any one brain pathway is used. By cutting off unused pathways, the brain eventually settles into a structure that's most efficient for the owner of that brain, creating well-worn grooves for the pathways that person uses most. Synaptic pruning intensifies after rapid brain-cell proliferation during childhood and again in the period that encompasses adolescence and the 20s. It is the mechanism of "use it or lose it": the brains we have are shaped largely in response to the demands made of them.

We have come to accept the idea that environmental influences in the first three years of life have long-term consequences for cognition, emotional control, attention and the like. Is it time to place a similar emphasis, with hopes for a similar outcome, on enriching the cognitive environment of people in their 20s?

N.I.M.H. scientists also found a time lag between the growth of the limbic system, where emotions originate, and of the prefrontal cortex, which manages those emotions. The limbic system explodes during puberty, but the prefrontal cortex keeps maturing for another 10 years. Giedd said it is logical to suppose - and for now, neuroscientists have to make a lot of logical suppositions - that when the limbic system is fully active but the cortex is still being built, emotions might outweigh ration ality. "The prefrontal part is the part that allows you to control your impulses, come up with a long-range strategy, answer the question ‘What am I going to do with my life?' " he told me. "That weighing of the future keeps changing into the 20s and 30s."

Among study subjects who enrolled as children, M.R.I. scans have been done so far only to age 25, so scientists have to make another logical supposition about what happens to the brain in the late 20s, the 30s and beyond. Is it possible that the brain just keeps changing and pruning, for years and years? "Guessing from the shape of the growth curves we have," Giedd's colleague Philip Shaw wrote in an e-mail message, "it does seem that much of the gray matter," where synaptic pruning takes place, "seems to have completed its most dramatic structural change" by age 25. For white matter, where insulation that helps impulses travel faster continues to form, "it does look as if the curves are still going up, suggesting continued growth" after age 25, he wrote, though at a slower rate than before.

None of this is new, of course; the brains of young people have always been works in progress, even when we didn't have sophisticated scanning machinery to chart it precisely. Why, then, is the youthful brain only now arising as an explanation for why people in their 20s are seeming a bit unfinished? Maybe there's an analogy to be found in the hierarchy of needs, a theory put forth in the 1940s by the psychologist Abraham Maslow. According to Maslow, people can pursue more elevated goals only after their basic needs of food, shelter and sex have been met. What if the brain has its own hierarchy of needs? When people are forced to adopt adult responsibilities early, maybe they just do what they have to do, whether or not their brains are ready. Maybe it's only now, when young people are allowed to forestall adult obligations without fear of public censure, that the rate of societal maturation can finally fall into better sync with the maturation of the brain.

Cultural expectations might also reinforce the delay. The "changing timetable for adulthood" has, in many ways, become internalized by 20-somethings and their parents alike. Today young people don't expect to marry until their late 20s, don't expect to start a family until their 30s, don't expect to be on track for a rewarding career until much later than their parents were. So they make decisions about their futures that reflect this wider time horizon. Many of them would not be ready to take on the trappings of adulthood any earlier even if the opportunity arose; they haven't braced themselves for it.

Nor do parents expect their children to grow up right away - and they might not even want them to. Parents might regret having themselves jumped into marriage or a career and hope for more considered choices for their children. Or they might want to hold on to a reassuring connection with their children as the kids leave home. If they were "helicopter parents" - a term that describes heavily invested parents who hover over their children, swooping down to take charge and solve problems at a moment's notice - they might keep hovering and problem-solving long past the time when their children should be solving problems on their own. This might, in a strange way, be part of what keeps their grown children in the limbo between adolescence and adulthood. It can be hard sometimes to tease out to what extent a child doesn't quite want to grow up and to what extent a parent doesn't quite want to let go.

IT IS A BIG DEAL IN developmental psychology to declare the existence of a new stage of life, and Arnett has devoted the past 10 years to making his case. Shortly after his American Psychologist article appeared in 2000, he and Jennifer Lynn Tanner, a developmental psychologist at Rutgers University, convened the first conference of what they later called the Society for the Study of Emerging Adulthood. It was held in 2003 at Harvard with an attendance of 75; there have been three more since then, and last year's conference, in Atlanta, had more than 270 attendees. In 2004 Arnett published a book, "Emerging Adulthood: The Winding Road From the Late Teens Through the Twenties," which is still in print and selling well. In 2006 he and Tanner published an edited volume, "Emerging Adults in America: Coming of Age in the 21st Century," aimed at professionals and academics. Arnett's college textbook, "Adolescence and Emerging Adulthood: A Cultural Approach," has been in print since 2000 and is now in its fourth edition. Next year he says he hopes to publish another book, this one for the parents of 20-somethings.

If all Arnett's talk about emerging adulthood sounds vaguely familiar . . . well, it should. Forty years ago, an article appeared in The American Scholar that declared "a new stage of life" for the period between adolescence and young adulthood. This was 1970, when the oldest members of the baby boom generation - the parents of today's 20-somethings - were 24. Young people of the day "can't seem to ‘settle down,' " wrote the Yale psychologist Kenneth Keniston. He called the new stage of life "youth."

Keniston's description of "youth" presages Arnett's description of "emerging adulthood" a generation later. In the late '60s, Keniston wrote that there was "a growing minority of post-adolescents [who] have not settled the questions whose answers once defined adulthood: questions of relationship to the existing society, questions of vocation, questions of social role and lifestyle." Whereas once, such aimlessness was seen only in the "unusually creative or unusually disturbed," he wrote, it was becoming more common and more ordinary in the baby boomers of 1970. Among the salient characteristics of "youth," Keniston wrote, were "pervasive ambivalence toward self and society," "the feeling of absolute freedom, of living in a world of pure possibilities" and "the enormous value placed upon change, transformation and movement" - all characteristics that Arnett now ascribes to "emerging adults."

Arnett readily acknowledges his debt to Keniston; he mentions him in almost everything he has written about emerging adulthood. But he considers the '60s a unique moment, when young people were rebellious and alienated in a way they've never been before or since. And Keniston's views never quite took off, Arnett says, because "youth" wasn't a very good name for it. He has called the label "ambiguous and confusing," not nearly as catchy as his own "emerging adulthood."

For whatever reason Keniston's terminology faded away, it's revealing to read his old article and hear echoes of what's going on with kids today. He was describing the parents of today's young people when they themselves were young - and amazingly, they weren't all that different from their own children now. Keniston's article seems a lovely demonstration of the eternal cycle of life, the perennial conflict between the generations, the gradual resolution of those conflicts. It's reassuring, actually, to think of it as recursive, to imagine that there must always be a cohort of 20-somethings who take their time settling down, just as there must always be a cohort of 50-somethings who worry about it.

KENISTON CALLED IT youth, Arnett calls it emerging adulthood; whatever it's called, the delayed transition has been observed for years. But it can be in fullest flower only when the young person has some other, nontraditional means of support - which would seem to make the delay something of a luxury item. That's the impression you get reading Arnett's case histories in his books and articles, or the essays in "20 Something Manifesto," an anthology edited by a Los Angeles writer named Christine Hassler. "It's somewhat terrifying," writes a 25-year-old named Jennifer, "to think about all the things I'm supposed to be doing in order to ‘get somewhere' successful: ‘Follow your passions, live your dreams, take risks, network with the right people, find mentors, be financially responsible, volunteer, work, think about or go to grad school, fall in love and maintain personal well-being, mental health and nutrition.' When is there time to just be and enjoy?" Adds a 24-year-old from Virginia: "There is pressure to make decisions that will form the foundation for the rest of your life in your 20s. It's almost as if having a range of limited options would be easier."

While the complaints of these young people are heartfelt, they are also the complaints of the privileged. Julie, a 23-year-old New Yorker and contributor to "20 Something Manifesto," is apparently aware of this. She was coddled her whole life, treated to French horn lessons and summer camp, told she could do anything. "It is a double-edged sword," she writes, "because on the one hand I am so blessed with my experiences and endless options, but on the other hand, I still feel like a child. I feel like my job isn't real because I am not where my parents were at my age. Walking home, in the shoes my father bought me, I still feel I have yet to grow up."

Despite these impressions, Arnett insists that emerging adulthood is not limited to young persons of privilege and that it is not simply a period of self-indulgence. He takes pains in "Emerging Adulthood" to describe some case histories of young men and women from hard-luck backgrounds who use the self-focus and identity exploration of their 20s to transform their lives.

One of these is the case history of Nicole, a 25-year-old African-American who grew up in a housing project in Oakland, Calif. At age 6, Nicole, the eldest, was forced to take control of the household after her mother's mental collapse. By 8, she was sweeping stores and baby-sitting for money to help keep her three siblings fed and housed. "I made a couple bucks and helped my mother out, helped my family out," she told Arnett. She managed to graduate from high school, but with low grades, and got a job as a receptionist at a dermatology clinic. She moved into her own apartment, took night classes at community college and started to excel. "I needed to experience living out of my mother's home in order to study," she said.

In his book, Arnett presents Nicole as a symbol of all the young people from impoverished backgrounds for whom "emerging adulthood represents an opportunity - maybe a last opportunity - to turn one's life around." This is the stage where someone like Nicole can escape an abusive or dysfunctional family and finally pursue her own dreams. Nicole's dreams are powerful - one course away from an associate degree, she plans to go on for a bachelor's and then a Ph.D. in psychology - but she has not really left her family behind; few people do. She is still supporting her mother and siblings, which is why she works full time even though her progress through school would be quicker if she found a part-time job. Is it only a grim pessimist like me who sees how many roadblocks there will be on the way to achieving those dreams and who wonders what kind of freewheeling emerging adulthood she is supposed to be having?

Of course, Nicole's case is not representative of society as a whole. And many parents - including those who can't really afford it - continue to help their kids financially long past the time they expected to. Two years ago Karen Fingerman, a developmental psychologist at Purdue University, asked parents of grown children whether they provided significant assistance to their sons or daughters. Assistance included giving their children money or help with everyday tasks (practical assistance) as well as advice, companionship and an attentive ear. Eighty-six percent said they had provided advice in the previous month; less than half had done so in 1988. Two out of three parents had given a son or daughter practical assistance in the previous month; in 1988, only one in three had.

Fingerman took solace in her findings; she said it showed that parents stay connected to their grown children, and she suspects that both parties get something out of it. The survey questions, after all, referred not only to dispensing money but also to offering advice, comfort and friendship. And another of Fingerman's studies suggests that parents' sense of well-being depends largely on how close they are to their grown children and how their children are faring - objective support for the adage that you're only as happy as your unhappiest child. But the expectation that young men and women won't quite be able to make ends meet on their own, and that parents should be the ones to help bridge the gap, places a terrible burden on parents who might be worrying about their own job security, trying to care for their aging parents or grieving as their retirement plans become more and more of a pipe dream.

This dependence on Mom and Dad also means that during the 20s the rift between rich and poor becomes entrenched. According to data gathered by the Network on Transitions to Adulthood, a research consortium supported by the John D. and Catherine T. MacArthur Foundation, American parents give an average of 10 percent of their income to their 18- to 21-year-old children. This percentage is basically the same no matter the family's total income, meaning that upper-class kids tend to get more than working-class ones. And wealthier kids have other, less obvious, advantages. When they go to four-year colleges or universities, they get supervised dormitory housing, health care and alumni networks not available at community colleges. And they often get a leg up on their careers by using parents' contacts to help land an entry-level job - or by using parents as a financial backup when they want to take an interesting internship that doesn't pay.

"You get on a pathway, and pathways have momentum," Jennifer Lynn Tanner of Rutgers told me. "In emerging adulthood, if you spend this time exploring and you get yourself on a pathway that really fits you, then there's going to be this snowball effect of finding the right fit, the right partner, the right job, the right place to live. The less you have at first, the less you're going to get this positive effect compounded over time. You're not going to have the same acceleration."

EVEN ARNETT ADMITS that not every young person goes through a period of "emerging adulthood." It's rare in the developing world, he says, where people have to grow up fast, and it's often skipped in the industrialized world by the people who marry early, by teenage mothers forced to grow up, by young men or women who go straight from high school to whatever job is available without a chance to dabble until they find the perfect fit. Indeed, the majority of humankind would seem to not go through it at all. The fact that emerging adulthood is not universal is one of the strongest arguments against Arnett's claim that it is a new developmental stage. If emerging adulthood is so important, why is it even possible to skip it?

"The core idea of classical stage theory is that all people - underscore ‘all' - pass through a series of qualitatively different periods in an invariant and universal sequence in stages that can't be skipped or reordered," Richard Lerner, Bergstrom chairman in applied developmental science at Tufts University, told me. Lerner is a close personal friend of Arnett's; he and his wife, Jacqueline, who is also a psychologist, live 20 miles from Worcester, and they have dinner with Arnett and his wife on a regular basis.

"I think the world of Jeff Arnett," Lerner said. "I think he is a smart, passionate person who is doing great work - not only a smart and productive scholar, but one of the nicest people I ever met in my life."

No matter how much he likes and admires Arnett, however, Lerner says his friend has ignored some of the basic tenets of developmental psychology. According to classical stage theory, he told me, "you must develop what you're supposed to develop when you're supposed to develop it or you'll never adequately develop it."

When I asked Arnett what happens to people who don't have an emerging adulthood, he said it wasn't necessarily a big deal. They might face its developmental tasks - identity exploration, self-focus, experimentation in love, work and worldview - at a later time, maybe as a midlife crisis, or they might never face them at all, he said. It depends partly on why they missed emerging adulthood in the first place, whether it was by circumstance or by choice.

No, said Lerner, that's not the way it works. To qualify as a developmental stage, emerging adulthood must be both universal and essential. "If you don't develop a skill at the right stage, you'll be working the rest of your life to develop it when you should be moving on," he said. "The rest of your development will be unfavorably altered." The fact that Arnett can be so casual about the heterogeneity of emerging adulthood and its existence in some cultures but not in others - indeed, even in some people but not in their neighbors or friends - is what undermines, for many scholars, his insistence that it's a new life stage.

Why does it matter? Because if the delay in achieving adulthood is just a temporary aberration caused by passing social mores and economic gloom, it's something to struggle through for now, maybe feeling a little sorry for the young people who had the misfortune to come of age in a recession. But if it's a true life stage, we need to start rethinking our definition of normal development and to create systems of education, health care and social supports that take the new stage into account.

The Network on Transitions to Adulthood has been issuing reports about young people since it was formed in 1999 and often ends up recommending more support for 20-somethings. But more of what, exactly? There aren't institutions set up to serve people in this specific age range; social services from a developmental perspective tend to disappear after adolescence. But it's possible to envision some that might address the restlessness and mobility that Arnett says are typical at this stage and that might make the experimentation of "emerging adulthood" available to more young people. How about expanding programs like City Year, in which 17- to 24-year-olds from diverse backgrounds spend a year mentoring inner-city children in exchange for a stipend, health insurance, child care, cellphone service and a $5,350 education award? Or a federal program in which a government-sponsored savings account is created for every newborn, to be cashed in at age 21 to support a year's worth of travel, education or volunteer work - a version of the "baby bonds" program that Hillary Clinton mentioned during her 2008 primary campaign? Maybe we can encourage a kind of socially sanctioned " rumspringa," the temporary moratorium from social responsibilities some Amish offer their young people to allow them to experiment before settling down. It requires only a bit of ingenuity - as well as some societal forbearance and financial commitment - to think of ways to expand some of the programs that now work so well for the elite, like the Fulbright fellowship or the Peace Corps, to make the chance for temporary service and self-examination available to a wider range of young people.

A century ago, it was helpful to start thinking of adolescents as engaged in the work of growing up rather than as merely lazy or rebellious. Only then could society recognize that the educational, medical, mental-health and social-service needs of this group were unique and that investing in them would have a payoff in the future. Twenty-somethings are engaged in work, too, even if it looks as if they are aimless or failing to pull their weight, Arnett says. But it's a reflection of our collective attitude toward this period that we devote so few resources to keeping them solvent and granting them some measure of security.

THE KIND OF SERVICES that might be created if emerging adulthood is accepted as a life stage can be seen during a visit to Yellowbrick, a residential program in Evanston, Ill., that calls itself the only psychiatric treatment facility for emerging adults. "Emerging adults really do have unique developmental tasks to focus on," said Jesse Viner, Yellowbrick's executive medical director. Viner started Yellowbrick in 2005, when he was working in a group psychiatric practice in Chicago and saw the need for a different way to treat this cohort. He is a soft-spoken man who looks like an accountant and sounds like a New Age prophet, peppering his conversation with phrases like "helping to empower their agency."

"Agency" is a tricky concept when parents are paying the full cost of Yellowbrick's comprehensive residential program, which comes to $21,000 a month and is not always covered by insurance. Staff members are aware of the paradox of encouraging a child to separate from Mommy and Daddy when it's on their dime. They address it with a concept they call connected autonomy, which they define as knowing when to stand alone and when to accept help.

Patients come to Yellowbrick with a variety of problems: substance abuse, eating disorders, depression, anxiety or one of the more severe mental illnesses, like schizophrenia or bipolar disorder, that tend to appear in the late teens or early 20s. The demands of imminent independence can worsen mental-health problems or can create new ones for people who have managed up to that point to perform all the expected roles - son or daughter, boyfriend or girlfriend, student, teammate, friend - but get lost when schooling ends and expected roles disappear. That's what happened to one patient who had done well at a top Ivy League college until the last class of the last semester of his last year, when he finished his final paper and could not bring himself to turn it in.

The Yellowbrick philosophy is that young people must meet these challenges without coddling or rescue. Up to 16 patients at a time are housed in the Yellowbrick residence, a four-story apartment building Viner owns. They live in the apartments - which are large, sunny and lavishly furnished - in groups of three or four, with staff members always on hand to teach the basics of shopping, cooking, cleaning, scheduling, making commitments and showing up.

Viner let me sit in on daily clinical rounds, scheduled that day for C., a young woman who had been at Yellowbrick for three months. Rounds are like the world's most grueling job interview: the patient sits in front alongside her clinician "advocate," and a dozen or so staff members are arrayed on couches and armchairs around the room, firing questions. C. seemed nervous but pleased with herself, frequently flashing a huge white smile. She is 22, tall and skinny, and she wore tiny denim shorts and a big T-shirt and vest. She started to fall apart during her junior year at college, plagued by binge drinking and anorexia, and in her first weeks at Yellowbrick her alcohol abuse continued. Most psychiatric facilities would have kicked her out after the first relapse, said Dale Monroe-Cook, Yellowbrick's vice president of clinical operations. "We're doing the opposite: we want the behavior to unfold, and we want to be there in that critical moment, to work with that behavior and help the emerging adult transition to greater independence."

The Yellowbrick staff let C. face her demons and decide how to deal with them. After five relapses, C. asked the staff to take away her ID so she couldn't buy alcohol. Eventually she decided to start going to meetings of Alcoholics Anonymous.

At her rounds in June, C. was able to report that she had been alcohol-free for 30 days. Jesse Viner's wife, Laura Viner, who is a psychologist on staff, started to clap for her, but no one else joined in. "We're on eggshells here," Gary Zurawski, a clinical social worker specializing in substance abuse, confessed to C. "We don't know if we should congratulate you too much." The staff was sensitive about taking away the young woman's motivation to improve her life for her own sake, not for the sake of getting praise from someone else.

C. took the discussion about the applause in stride and told the staff she had more good news: in two days she was going to graduate. On time.

THE 20S ARE LIKE the stem cell of human development, the pluripotent moment when any of several outcomes is possible. Decisions and actions during this time have lasting ramifications. The 20s are when most people accumulate almost all of their formal education; when most people meet their future spouses and the friends they will keep; when most people start on the careers that they will stay with for many years. This is when adventures, experiments, travels, relationships are embarked on with an abandon that probably will not happen again.

Does that mean it's a good thing to let 20-somethings meander - or even to encourage them to meander - before they settle down? That's the question that plagues so many of their parents. It's easy to see the advantages to the delay. There is time enough for adulthood and its attendant obligations; maybe if kids take longer to choose their mates and their careers, they'll make fewer mistakes and live happier lives. But it's just as easy to see the drawbacks. As the settling-down sputters along for the "emerging adults," things can get precarious for the rest of us. Parents are helping pay bills they never counted on paying, and social institutions are missing out on young people contributing to productivity and growth. Of course, the recession complicates things, and even if every 20-something were ready to skip the "emerging" moratorium and act like a grown-up, there wouldn't necessarily be jobs for them all. So we're caught in a weird moment, unsure whether to allow young people to keep exploring and questioning or to cut them off and tell them just to find something, anything, to put food on the table and get on with their lives.

Arnett would like to see us choose a middle course. "To be a young American today is to experience both excitement and uncertainty, wide-open possibility and confusion, new freedoms and new fears," he writes in "Emerging Adulthood." During the timeout they are granted from nonstop, often tedious and dispiriting responsibilities, "emerging adults develop skills for daily living, gain a better understanding of who they are and what they want from life and begin to build a foundation for their adult lives." If it really works that way, if this longer road to adulthood really leads to more insight and better choices, then Arnett's vision of an insightful, sensitive, thoughtful, content, well-honed, self-actualizing crop of grown-ups would indeed be something worth waiting for.