The ultimate American quest is to eliminate death. All those health stories that cite "premature" deaths from heart disease or cancer never quite say compared to what. The silent assumption is that any death is premature and that immortality is within our reach. If this seems absurd, consider what we've already done. Our culture is quietly erasing the idea of age. All ages are blurring with all other ages. Children shall become grown up as soon as possible. Young adults shall remain children as long as possible. Middle age barely exists, except as a graceful state reserved for those who were once considered old.

No one is supposed to grow old until entering a nursing home. We simply retire, entitling us to do things that we did (or could have done) as children -- watch TV all day (now, surf the Net), take long trips, attend college or play softball. Increasingly, the elderly resent being called "elderly." In one survey, 40 percent of retirees labeled the term objectionable. The ageless society starts when children begin to act -- just like everyone else -- as consumers. American Demographics magazine (which caters to corporate marketers) reports that in 1998 children 6 to 11 spent $25 billion of their money and influenced another $187 billion. In five years, children's spending has doubled -- an increase the magazine attributed to "bigger allowances, more dual-income families, and greater childhood freedom." Parents no longer preach "anti-consumerist values" to children, the magazine suggested.

The rush toward adulthood accelerates as children pass third or fourth grade. Pop culture for the young and old is converging. "The Simpsons" indoctrinates the young into adult hypocrisy and cynicism. Indeed, "The Simpsons" epitomizes the triumph of ageless culture. The brilliant writing appeals (at different levels) to viewers of all ages. Various TV series for teens ("Dawson's Creek," "Party of Five") share a common plot line: Being grown up means thinking exclusively about sex. A few decades ago, these series might have been considered too explicit for adults, let alone teens. Along with cultural parity, the young often crave economic independence from parents. Among teens 16 to 19, almost half hold jobs.

The contradiction is that, having dashed into adulthood, younger Americans then cling to many childhood pleasures -- the avoidance of commitment, the worship of fun. A study by sociologists Elizabeth Cooksey of Ohio State University and Ronald Rindfuss of the University of North Carolina finds that "crisp, irreversible, and unambiguous" boundaries between adolescence and adulthood barely exist. People mix work and school. Even among white men ages 25 to 31, only 63 percent held jobs consistently for a six-year study period. Naturally, marriage is postponed. In 1950 the median age for first marriages was 23 for men and 20 for women; by 1990, those ages were 26 and 24. The self-absorbed and aimless characters in "Friends" may be stereotypes, but they're not completely removed from reality.

Historically, an ageless society is nothing new. Until this century, children worked in homes, fields or factories almost as soon as they could. The economic historian Stuart Bruchey tells us that 55 percent of the cotton mill workers in Rhode Island in 1820 were children. In 1826, one 19-year old became a mill superintendent because he'd already been there for 11 years. In the late 19th century, rural families "almost universally . . . [depended] on the labor of their children," Bruchey notes. In a new book ("The Rise and Fall of the American Teenager"), Thomas Hine reports that "teenager" is a relatively new life stage. Through the 1920s, Hine says, most teens got jobs. A high school diploma marked someone as middle class, while dropping out "in the first or second year indicated membership in the working class."

The Great Depression put teens out of work and made their working undesirable (scarce jobs should go to adults). Increasingly, they stayed in school. "Once a large majority started going to high school, all of them, regardless of their economic or social status, began to be seen as members of a single group," writes Hine in American Heritage magazine. The term "teenager" wasn't first used in print until 1941, he says. Retirement is also a modern creation. Until the 1930s, most men worked until their bodies gave way -- and Americans didn't live that long anyway. In 1900, life expectancy at birth was 47 years; now it is 76.

Past agelessness reflected poverty. In 1900 marriage ages were almost the same as today's. Men waited until they had income; women wanted a breadwinner. By contrast, today's agelessness reflects prosperity.

"Fabulous in their 40s," says a recent cover of People magazine featuring actresses Rene Russo (45), Andie MacDowell (41) and Kim Basinger (45). "Here's how the hottest women in Hollywood keep feeling sexy -- and looking it too," says the magazine. Their appeal is not just to men. It's to "21 million American women [in their forties who] look and feel better than their forerunners . . . and they're eager to see the fullness of their lives reflected on screen." A new survey from the AARP (which last year stopped calling itself the American Association of Retired Persons) plugs the sexuality of older people. Among those 60 to 74, about 30 percent of men and 24 percent of women report having sex at least once a week.

Every social revolution has its holdouts. Writing recently in the New York Times, Melvin Maddocks (described as a retired 70-something newspaper columnist) dismissed "the so-called new friskiness" among the old as a fantasy of baby boomers intended to dispel their own "terror of ending up, heaven forbid, like their parents." Some young people may also have missed the message. Though pop culture is drenched in sex, teens are actually having less sex. And countless studies show that children fare best when well connected to parents (read adults). Still, agelessness seems unstoppable, because it embodies that modern American ideal -- self-fulfillment. Expressed differently, we all ought to do anything we want whenever we want.