There's something about the outdoors — something essential — that Lynn Van Horne and her husband, Kurth Chin Fatt, must have.

The couple hike most Saturdays and often shape their vacations around backpacking and camping. "My husband and I have backpacked to the bottom of the Grand Canyon six times," said Van Horne, an elementary school teacher. "It is the most amazing thing. We come home rejuvenated and completely relaxed. You are so in the moment that your brain is completely rested from anything stressful."

Call it nature's cure.

Though the present-day "built environment" — the infrastructure of cities and suburbs and their accouterments — has greatly insulated us from this nature of ancient mankind, our bond is not easily relinquished. In fact, research into humanity's relationship with nature — or lack of it — is finding that it can be a salve for mind, body and spirit.

Nature can be as big as a national park or as finite as a backyard that beckons children to frolic and explore. And it is our nature, so to speak, to be amongst it. "We've evolved in nature," says Frank Farley, a psychologist at Temple University in Philadelphia. It is part of our fabric, left over from ancestors who once foraged and hunted on the African savanna.

Spending time with Mother Earth — whether it's gazing out a window, tending a garden or relaxing at the seashore — can quiet the mind, boost creativity and self-esteem, and lead to an acceptance of self and spiritual connection. Hiking, running, paddling or other outside exercise also spurs the pituitary gland's production of "feel-good" endorphins.

Push nature away and the consequences can be far-reaching, especially for children.

Researchers for the last decade are just beginning to learn that people are greatly influenced by green.

Frances Kuo, director of the University of Illinois' Human Environment Research Laboratory in Urbana-Champaign, Ill., says studies in Chicago's inner-city neighborhoods have suggested that even meager trees and grass can lessen violence and promote a feeling of safety and the formation of social ties. Another study there found children with attention-deficit hyperactivity disorder had a marked reduction in symptoms when they got daily "green time" outdoors.

Research at the University of Michigan suggests that workers who can see nature through windows are less stressed and bored and like their jobs more than those without windows. Other research has connected faster healing times and a decrease in anxiety in hospital patients who had rooms with views of the natural world.

Winter Park, Fla., artist and conservationist Rebecca Eagan, 52, fondly remembers a childhood filled with family camping trips, horseback riding and blackberry picking in the Florida woods. "We took it for granted. It was just part of life," she says. "Those little nature experiences were just always there. ... I loved being out in it."

But the free-rein childhoods remembered by such baby boomers are now more of an exception than a rule, says Richard Louv, author of "Last Child in the Woods: Saving Our Children from Nature-Deficit Disorder." Today, development gobbles up land once roamed by kids, and homeowner associations often prohibit things such as basketball goalpoasts and playhouses. After-school programs might shy away from injury-prone playground time in favor of indoor crafts and games, and latchkey kids lock themselves in until a parent or caregiver arrives home.

In his book, Louv writes of what they miss: "Nature offers healing for a child living in a destructive family or neighborhood. It serves as a blank slate upon which a child draws and reinterprets the culture's fantasies. Nature inspires creativity in a child by demanding visualization and the full use of the senses."

In today's world, that can translate into children experiencing nature with parents present. Fear of "stranger danger" is not likely to disappear from most people's lives.

It's an excellent idea, says psychologist Farley. "Kids often will look at parents and see them as sort of stuffy — not very adventurous, not risk-takers." Taking the family on an adventure, however mild, can build respect as well as the parent-child bond.

For troubled youths, nature can serve as a therapist. "You get them out into a more adventurous world, and it has a high stimulation value. ... It's a thrill, it's exciting, it's satisfying, it's rewarding," he says. "Nature helps to ground us in a larger world in a historic context." It lets us know we are part of a system of other living things that thrive or struggle much as we do.

Taking time for a walk on the beach or a romp in a park sends an important message. However, "we're not modeling this to our children," observes schoolteacher Van Horne. "When we're home, there's always something we have to do. When you backpack three miles into the woods, once you're out there, there's nothing to do. It's a freedom. All of a sudden you're just sitting and enjoying, sitting around the campfire and doing nothing. It's having no structure, and not having a TV on and not going on the computer."

Adds Farley, "The more we can do to reconnect, the better in my view, so that we come to understand more about self and relationship to the world around us and our evolutionary history and our place in nature."