Floating in the redwood hot tub with her head tilted back against a pillow, my friend Jane looked up through the pines toward an incredible array of stars splashed across the night sky, then took a long, deep breath all the way down to her toes.

For the first time in months, she wasn't soothing clients, hauling dogs to obedience school, tackling small boys covered with peanut butter, or listening to a husband in the midst of corporate warfare.

Instead, she was soaking in 102 F water, inhaling the heavy night scents of the forest, and playing with my yellow rubber ducky. And she was talking. She was talking about her mom, her sisters, her work, her husband, her children, and the business she had built from scratch.

Everything was on the table. And it would be until we'd picked apart all the threads that colored her life, then woven them back together.

Friendships between women are special. They shape who we are and who we are yet to be. They soothe our tumultuous inner world, fill the emotional gaps in our marriage, and help us remember who we really are. But they may do even more. Scientists now suspect that hanging out with our friends can actually counteract the kind of stomach-quivering stress most of us experience on a daily basis.

A landmark UCLA study suggests that women respond to stress with a cascade of brain chemicals that cause us to make and maintain friendships with other women. It's a stunning finding that has turned five decades of stress research -- most of it on men -- upside down.

"Until this study was published, scientists generally believed that when people experience stress, they trigger a hormonal cascade that revs the body to either stand and fight or flee as fast as possible," explains Laura Cousino Klein, PhD, now an assistant professor of biobehavioral health at Pennsylvania State University in State College, and one of the study's authors. It's an ancient survival mechanism left over from the time we were chased across the planet by saber-toothed tigers. Now the researchers suspect that women have a larger behavioral repertoire than just "fight or flight."

In fact, says Dr. Klein, it seems that when the hormone oxytocin is released as part of the stress response in a woman, it buffers the fight or flight response and encourages her to tend children and gather with other women instead. When she actually engages in this tending or befriending, studies suggest that more oxytocin is released, which further counters stress and produces a calming effect. This calming response does not occur in men, says Dr. Klein, because testosterone -- which men produce in high levels when they're under stress -- seems to reduce the effects of oxytocin. Estrogen, she adds, seems to enhance it.

The discovery that women respond to stress differently than men was made in a classic "aha!" moment shared by two women scientists who were talking one day in a lab at UCLA.

"There was this joke that when the women who worked in the lab were stressed, they came in, cleaned the lab, had coffee and bonded," says Dr. Klein. "When the men were stressed, they holed up somewhere on their own.

"I commented one day to fellow researcher Shelley Taylor that nearly 90 percent of the stress research is on males. I showed her the data from my lab, and the two of us knew instantly that we were onto something." The women cleared their schedules and started meeting with one scientist after another from various research specialties.

Very quickly, Drs. Klein and Taylor discovered that by not including women in stress research, scientists had made a huge mistake: The fact that women respond to stress differently than men has significant implications for our health.

It may take some time for new studies to reveal all the ways that oxytocin encourages us to care for children and hang out with other women, but the "tend and befriend" notion developed by Drs. Klein and Taylor may explain why women consistently outlive men. Study after study has found that social ties reduce our risk of disease by lowering blood pressure, heart rate and cholesterol. "There's no doubt," says Dr. Klein, "that friends are helping us live longer."

In one study, for example, researchers found that people who had no friends increased their risk of death over a six-month period. In another study, those who had the most friends over a nine-year period cut their risk of death by more than 60 percent.

Friends are also helping us live better. The famed Nurses' Health Study from Harvard Medical School found that the more friends women had, the less likely they were to develop physical impairments as they aged, and the more likely they were to be leading a joyful life. In fact, the results were so significant, the researchers concluded, that not having a close friend or confidante was as detrimental to your health as smoking or carrying extra weight!

And that's not all: When the researchers looked at how well the women functioned after the death of their spouse, they found that even in the face of this biggest stressor of all, those women who had a close friend and confidante were more likely to survive the experience without any new physical impairment or permanent loss of vitality. Those without friends were not always so fortunate.

Thinking of my stepmother, Edna, and her friends, this certainly makes sense. When Edna lost her first husband at age 62, she was shattered. But her friend Gloria (also a widow) took her under her wing and introduced her to a group of women at church who counted the offering every Sunday. And when their friends Fern and Sally lost their husbands, the four women dubbed themselves "The Merry Widows." They frequently met for lunches and dinners, and they even took trips abroad. The women survived for a couple of decades beyond their husbands, and one of them -- my beloved stepmother -- was married and widowed again.

Now 84, Edna still sells real estate, handles truculent tenants, lunches with friends and flies around the U.S. visiting family. Part of her ability to be so active is simply because Edna is Edna. But I often wonder how much of her ability to do so much and stay so healthy has been because of her friends Gloria, Fern and Sally.

Yet if friends counter the stress that seems to swallow up so much of our life these days, if they keep us healthy and even add years to our life, why is it so hard to find time to be with them? That's a question that also troubles researcher Ruthellen Josselson, PhD, coauthor of Best Friends: The Pleasures and Perils of Girls' and Women's Friendships (Three Rivers Press, 1998). "Every time we get overly busy with work and family, the first thing we do is let go of friendships with other women," explains Dr. Josselson. "We push them right to the back burner. That's really a mistake, because women are such a source of strength to each other. We nurture one another. And we need to have unpressured space in which we can do the special kind of talk that women do when they're with other women. It's a very healing experience."

Sitting on my deck as the sun drops behind the trees and the frogs down at the stream begin their nightly chorus, I think about Dr. Josselson's words and about my friend Debbie.

A few years ago when her children were small, Debbie worked a million hours a week as a Web designer and another zillion as supermom. With three kids who were into track, lacrosse, band, Scouts and school plays, Debbie was Harriet Nelson, Donna Reed and Brady mom Florence Henderson all rolled into one. If one of her kids wanted to play violin, Debbie made sure it happened. But the cost was high. She was exhausted. I was too, although with only one child, it was more from working so hard that I could hardly think straight.

Our friendship was paying the price. We'd been friends for 16 years, and if we were going to stay friends for another 16, we realized that we'd better make time for each other. So one day we parked the children with our husbands, posted the kids' schedules on the fridge and fled families, jobs and responsibilities for an early spring weekend at the Jersey shore.

We donned big sunglasses that hid our faces, turned up the radio until Debbie's white LeBaron convertible vibrated like a deranged boom box, whooped at strange guys in tight jeans -- well, I did, anyway -- and made it to the Somers Point liquor store in less than an hour to buy the most expensive bottle of wine we could find.

We talked the whole way. We were still talking while we walked on the empty beach for miles, picking up shells and dancing around the playful waves. We pigged out on seafood in the hotel's deserted dining room --cracking claws, licking our fingers and tossing our napkins into piles of butter-dribbled linen -- then returned to our room and dragged chairs, quilts and wineglasses out to the balcony overlooking the surf.

Two hours later, our words finally slowed, and we began to listen to the incessant sound of waves hissing on the sand. Debbie snuggled deeper into her chair, pulled the quilt up under her chin and sleepily asked what time it was.

I looked at my watch. "Nine o'clock. Are you going to sleep?"

"Mmm," she yawned from behind the quilt. "Maybe. Just don't tell the kids if I do. I told 'em we were gonna party all night."

And with sleepy chuckles that trailed off into the rustling beach grass, two exhausted friends finally stopped talking and slid into a deep, healing sleep.

While your childhood buddy will always be the sister of your heart, geography, jobs and life in general make that singular reliance on one another impossible. Part of growing up is expanding your heart and your circle of friends along with it. In that spirit, we think there are five chicks that every woman needs in her court: