GENEVA — You're between 45 and 55 years old, maybe have adult children. But judging from the clothes you wear and the way you speak, your hobbies and travels, you still act like a 30-year-old. They say you're an eternal teenager. You identify with the movie While We're Young. Don't feel bad, because for the first time in human history, age has actually gotten younger, says French sociologist Serge Guérin.

The so-called quincado is a "50-year-old teen." The French portmanteau designation appeared in 2013 to describe people of a certain age and sociocultural background living with, well, a particular zest. Men have been having mid-life crises forever, so this term mostly applies to women. The quincado is a baby boomer who grew up in the 1960s or 1970s and prefers freedom over authority, parties over chores, a chosen profession over suffered labor, improvised trips over organized holidays.

Women who meet this description sometimes have a lot in common with their adult daughters, with whom they share T-shirts and, sometimes, boyfriends. The male prototypes like video games, working out and parties that last until the early morning. Both are avid social network users. The quincado doesn't let herself or himself be confined, instead rejecting labels and shaping life one day at a time.

A fairytale life

Mylène is 55 but looks 10 years younger. For the past four years, the Parisian who formerly headed an advertisement agency has been keeping a blog, happyquinqua.com, and personifies the characteristics of this label. "A quincado? I think the term is quite unrefined, but I find it describes me," she says. "Since I sold my advertisement agency, I've been avoiding anything that could stress me out and, yes, my life is kind of a fairytale."

[rebelmouse-image 27089354 alt="""" original_size="1920x1080" expand=1]

Ben Stiller, Dre Hemingway Naomi Watts and Adam Driver in Noah Baumbach's While We're Young (2015)

She takes regular jogs in Parisian parks, makes frequent trips to New York through an apartment exchange website, consults for young companies, meets friends for coffee, attends cultural events, and enjoys reading and writing. Her everyday life is liberated.

"My partner, who's my age, is a creative person. He's perfectly OK with this way of doing things," she says.

So are her children. "Whether it's my 27-year-old son or my 22-year-old daughter living in New York, they both seem glad to have a dynamic mother free to do what she wants," she says. "Just last night, the three of us jammed together — my friend on the piano, my son on the guitar and me on vocals. We had a great time. As for my parents, I don't live in the same city as them, but I visit them every month and they support my choices. They're even quite proud, I think."

Mylène feels young but is also willing to undergo treatments to keep it that way. "First, I've always stayed out of the sun as much as I could, but for the past five years I've been having Botox injections, very moderately, once every two years," she says. "My esthetician also applies face masks and a pulsed light treatment. I'm against plastic surgery, because it betrays who we really are. But I couldn't not do anything with my circle of friends, who all secretly take action against the ravages of aging."

The idea of manipulating one's body to seem younger seems superficial, but it feels crucial to her. "Quincados don't reflect a refusal to age," says sociologist Serge Guérin. "They are the beneficiaries of objective rejuvenation. Just 15 years ago, people in their fifties who were laid off were finished. Now, people in their fifties who get fired start a new life, because they know their existence can still last for 40 or 50 more years."

People who resort to plastic surgery represent an entirely different mindset, he says. "They don't live with it. They move away from who they are, deny themselves, and that's problematic.

"I'm an adult child"

Guérin is the author of Silver Génération, a book that challenges 10 common misconceptions about aging. "Age is getting younger," he insists. "There have never been so many active 50-year-olds. It's the first time in history that this age corresponds to half a life. It's also the first time people reach the age of 50 in such good shape," whether physically or neurologically.

[rebelmouse-image 27089355 alt="""" original_size="612x612" expand=1]

No age limit for selfies — Photo: San Sharma

At 48, Sébastien is about to launch into a flamboyant quincado future. "It's true, I'm an adult child," he says. "I love strolling through toy departments and spend whole evenings playing video games. I also like using a pretend voice over the phone to prank people. And I also spend time with people who are at least 10 years younger than me. So I kind of speak like a younger person and make dirty jokes that shock my children, who are adults."

As Guérin says, "society must evolve and realize that at 50 today, we're not as old as we were just 15 years ago."

How do the 20- and 30-year-olds find their place in this new society full of silver foxes? "I'm against the idea of a generation war," Guérin adds. "Today, knowledge goes both ways. It's not unusual for an older adult to ask a young person to explain something, especially on the technological level. We all have our own legitimacy."

As for commanding authority, Mylène says that when she was raising her children, she always favored "love and autonomy." Guérin calls it a "sensitive" issue. "The 50-year-olds, from the post-1968 generation, when it was forbidden to forbid, often have a friend-to-friend relationship with their children," she says. "This can lead to differences regarding hierarchy, that's true."

The solution, he says, is mutual respect. "I'm against authoritarian relationships. But I'm for authority-based relationships," he says. "In other words, a relationship in which the 50-year-old knows his value and passes his experience on to the following generations."

Quincados, after all, may be fun, but they're not brainless.