Growing old begins around fourth grade.

The characteristics that keep us young — curiosity, wonder, play, acting silly — begin to get subverted then, says Ronda Beaman, 53 and mother of two and the author of "You're Only Young Twice: 10 Do-Overs to Reawaken Your Spirit" (VanderWyk & Burnham, $14.95).

"By then, most children learn what it takes to get good grades. They start playing the game. The characteristics of joy and wonder are just — 'Poof!' " says Beaman, president of Second Wind Inc., a midlife coaching firm, and adjunct faculty member at California Polytechnic State University in San Luis Obispo.

Beaman's own search for forestalling the march of time began on the brink of her 40th birthday. While a friend got a face-lift, Beaman found her elixir in a used-book store. It was a copy of anthropologist Ashley Montagu's 1988 book "Growing Young." Montagu introduced her to neoteny, the idea that human beings are built to grow and develop their childhood traits rather than minimize them.

"Simply put, neoteny is the process of growing young," Beaman says.

REVISIT YOUR YOUTH

Traits such as playfulness, curiosity, singing, dancing, loving, being creative, being joyful, laughing and crying — commonly associated with childhood — prolong youthfulness, she says.

Those traits are frequently used to describe older adults who are seen as thriving. Arizona State University gerontologist Kathleen Waldron says research long has shown that older people who are active are happier and healthier than those who are not active. A recent study among older women indicates that a love of learning, intellectual curiosity and creativity engender a youthful spirit, Waldron says.

In a culture idealizing youth, we often leave behind skills that can keep us alive and vital, Beaman argues.

"It's shown from hard science that we were intended to retain our sense of wonder and curiosity. These were traits given to us as children that we were meant to hold on to our whole life," she says.

Beaman says accessing the same playful nature you enjoyed as a child doesn't mean dismissing the struggles, pains and hardships of growing up.

BEYOND PLASTIC

Divorced and juggling single parenthood with the rigors of a tenure-track university faculty position, Beaman didn't want to ward off the images of growing old with endless self-talk, plastic surgery or avoidance.

That's why discovering Montagu's research that said nature built humans to maximize their youthful traits, not minimize them, led her into a 10-year research and book-writing project.

"The greatest asset our generation has is a second chance," she says. "In all of human history, the average life span for 99 percent of people was 18 years old. That was hardly a chance to grow young once." But baby boomers, born between 1946 and 1964, are looking at life spans that could reach into the 90s.

"No matter how much money you spend, no matter the surgeons' work or the vitamins you take, you're still going to accumulate years," she says. "It's not a sustainable model."

The way to rejuvenate yourself is to recapture the characteristics given us as a birthright, Beaman says.

"The opportunity is to die young as late as you can," she says. One of the first steps, she says, is to ask yourself what you liked doing when you were a child: "What did you laugh at? What did you like to do?"

"I'm still the kind of person who would throw a neighborhood carnival."