A friend spots a bumper sticker on sale in Australia: I refuse to get old. Such slogans used to be ironic in

intent. Amortals adopt them as mission statements, and the amortal form of positive thinking — refusing

to contemplate age and death — can bring positive results, up to a point. "Strictly speaking, longevity is

measured in numbers: it is the arithmetical accumulation of days, weeks, months and years that

produces our chronological life," wrote the psychiatrist and gerontologist Robert Butler in his last book,

The Longevity Prescription. "Yet aging — or, more accurately, its converse, staying young — is in no

small measure a state of mind that defies measurement."

That isn't a platitude, as Harvard psychology professor Ellen Langer set out to prove back in 1979. Her

experiment, designed to see to what extent people think themselves younger or older, started with the

retrofit of an isolated hotel in New England. The fixtures and fittings were exchanged for 1959 period

equivalents; the refrigerator was stocked with foodstuffs available 20 years earlier. Then came the guests:

men in their 70s and 80s, instructed not to view this as an exercise in nostalgia but to pretend they had

traveled back two decades in time.

This pretense proved decisive. A control group, taken from the same demographic, arrived to stay in the

hotel after the first contingent had left. Their experience differed only in one key respect: they were

allowed to acknowledge that this was an experiment and to reminisce about the world the retrofit evoked.

In just a week, both groups chalked up physical and cognitive improvements. But the changes were

much more pronounced among the time travelers.

It's a result that goes some way toward explaining the extraordinary sense of well-being that radiates

from the residents of Sun City Shadow Hills, a community for "active adults aged 55 and better" in

California's Coachella Valley, where retirement has been successfully reimagined not as a cessation of

work but as a long whirl of absorbing activity.

A construction magnate named Del Webb opened the first Sun City community in Arizona in 1960. "An

old fellow came up to me once with tears in his eyes and thanked me for building Sun City," recounted

Webb, interviewed for a 1962 TIME cover story. "He said he was planning to spend the happiest 40 years

of his life there." Webb died in 1974, but his creation lives on. There are now more than 50 Sun Cities

dotted across America. Sun City Shadow Hills, launched in 2004, is among the newest. Driving along its

flawless red macadam streets in yellow sunshine beneath unrealistically blue skies, you start to wonder if

you've strayed onto a back lot at a Hollywood studio. Distant figures shimmer in the heat haze on the

fairway, and a golf buggy hums along a perimeter road, but the sidewalks are empty. Then you ring the

doorbell at Patti and Phil Wolff's house and discover a fair chunk of Sun City's boisterous population

ensconced in their large open-plan kitchen. At the back of the house, there's a lush garden their

next-door neighbor describes as "bitchin'," and a barbecue sends aromatic smoke signals to the rest of

the community that one of Patti's famous meals will shortly be served. Patti, 63, describes one of her

most ambitious catering challenges: a 2010 dinner-dance that drew 81 guests, organized by the Rainbow

Club, the community's gay and lesbian social club. "When they told me what it was going to cost per

person just for the food, I said, 'Oh, come on, I can do that for half. And give you choices,'" she says.

Her husband Phil, also 63, is a different kind of dynamo. Connected to the mains, he could power his

whole street and its air-conditioned residences and 24-hour sprinkler systems. He plays softball, is a regular at the state-of-the-art gym at Sun City's 35,000-sq.-ft. (3,250 sq m) Montecito Clubhouse and

indulges a passion for cycling, racking up as many as 175 miles (280 km) per week. "Basically, he does

so many things that I hardly see him," says Patti. "It's like if he was back at work again."

The couple's action-packed lifestyle comes thanks to their erstwhile employer, telecom company Pacific

Bell, which featherbedded them into early retirement. Several of the friends around their table still work.

Larry Johnson, 63, once the manager of a funeral home in Oregon, these days offers a similar service for

pets, assisted by his partner Bruce Atkinson, 66. "Hundreds of people [in the area] have old dogs and

cats, and eventually those dogs and cats will die, so Larry gets a lot of business," says Atkinson.

The same forces that keep Johnson's business ticking will eventually disrupt the idyll that he and his

friends have built. For the moment, their community offers the ideal support network for widows and

widowers, but as their numbers inevitably swell, the network will contract. On a recent night out at

another Sun City development called Palm Desert, Johnson and Atkinson caught an uncomfortable

glimpse of the future. "We were standing there, and we both made the comment, 'God, these are really

old people,'" says Atkinson. Palm Desert opened 12 years before Shadow Hills; the average age of its

residents is higher. And because ownership of Sun City properties is restricted to the 55-pluses, the

communities age and risk dying off together. Yet it is the absence of young people that — for a while, at

least — revitalizes Sun City residents, permitting a powerful illusion of agelessness. Shielded like

Langer's test subjects from reminders of their chronological age, they become amortal.