A long line of the world's thinkers — from Immanuel Kant to William James to Deepak Chopra — have recommended we take walks in nature to relieve stress and refocus our thoughts. And nature writers — from Henry David Thoreau to John Muir to Edward Abbey — have extolled the restorative benefits of nature. "Everybody," Muir said, "needs beauty as well as bread, places to play in and pray in, where nature may heal and give strength to body and soul."
Turns out they were ahead of their time. "Attention Restoration Theory" or ART, which posits that a walk in the woods helps refocus the mind and revive the spirit, has been a growing field of research for the past 20 years. New studies are quantifying the restorative powers of nature and suggesting how the restorative process works.
"In the late 1980s, I discovered that 'favorite places' could be a good window [measurable unit of analysis] into how humans use their environment to restore themselves," states psychologist Kalevi Korpela with Finland's University of Tampere.
Korpela's most recent study questioned some 1,273 city dwellers of Helsinki and Tampere, aged 15 to 75 about the restorative experiences of their "favorite" places. Residents identified their favorite restorative places and what they perceived as the health benefits of visiting them.
The self-rated restorative benefits gained by venturing into the woods and along natural shorelines — "an early-morning walk is a blessing for the whole day," as Thoreau said — were judged as significantly stronger than ventures to other favorite places in the city, including developed parklands. The results revealed links between the need for restoration (relief from worries and stress about money, jobs and the hectic pace of modern life) and the use of favorite places — what the social scientists call "environmental self-regulation strategies" — to achieve restorative benefits.
The more worries (particularly about work and money) an individual had, the higher the typical level of restoration experience, and the more reported benefits gained from getting out into nature. Unfortunately, those with many worries had a low rate of nature trips and consequently received a lower level of restorative benefits.
"This inconsistency surprised us," Korpela says.
As social scientists explain it, nature engages your attention in relaxed fashion — leaves rustling, patterns of clouds, sunsets, a bird, the shape of an old tree. Nature captures our attention in subtle, bottom-up ways and allows our top-down attention abilities a chance to regenerate. Attention, therefore, is "restored" by exposure to natural environments.
But the artificial world, like a downtown city, demands active attention to avoid getting hit by cars, negotiate lights and intersections and navigate around others on the sidewalk. At the same time, city walkers are bombarded by advertisements, traffic and noise. The high-demand attention required when negotiating crowded city streets offers no rest for the weary mind; in fact, it's similar to the intellectual requirements demanded of office workers or of college students.
Nature's value in the recovery from illness has been quantified repeatedly. Studies have shown that post-surgery patients resting in rooms overlooking trees recovered better and faster than those in rooms with a view only of a brick wall. Another study demonstrated that women with breast cancer who walked in a park, watched birds or tended gardens recovered more quickly and were in better spirits than those with little or no contact with the natural world.
The cognitive benefits of nature — even if it's just a hint of nature like a poster or a potted plant — are many and have been tallied by a number of recent studies. University of Michigan researchers Marc Berman, John Jonides and Stephen Kaplan wanted to quantify the effects of ART. Students were given long tests of sequences of numbers to repeat in reverse then sent on walks — half the study participants on a nature walk and half on a city walk. Upon re-testing, the nature walkers' scores improved significantly while the city walkers' did not. The experiment was repeated so that each student walked in nature and in the city, and everyone's score was better after the nature walk.
Researcher Gary Felsten wanted to know the most restorative locations for study breaks and decided to ask students at the University of Chicago, a venue both academically intense and far removed from nature. Felsten took pictures of various lounge areas overlooking urban scenes and other buildings, others looking out on restful natural scenes. For some windowless lounges, he used computer software to place murals of natural scenes onto their empty walls.
Students were asked to rate the lounges for "a sense of being away" and other qualities considered by ART as "restorative." Students rated the lounges with both artificial and real views of nature as more restorative than views of the city.
Researchers around the world have shown that windows looking out on nature scenes deliver significant restorative results and are now inquiring about the possible benefits of "virtual" nature. Can technology in the form of nature scenes on a high-definition plasma screen provide a restorative "nature fix?" Researchers from the University of Washington's Human Interaction With Nature and Technological Systems Lab got mixed results from two studies: One study showed plasma nature windows providing low-level restorative benefits, another study showed them no more restorative than a blank wall.
One result of all of this research is that recognition of nature's mental and physical health value is now part of public health discussions. And ART research has helped legitimatize eco-psychology, long stereotyped as New Age philosophy and now seen as grounded in science and statistics.
If further research shows that people deprived of nature will display behaviors characteristic of fatigued attention and irritability, how should office buildings be designed? Schools? Neighborhoods?
Korpela sees the need for more studies about the use and effectiveness of natural and other favorite places in helping people regulate and reduce the stresses of everyday life.
"How do people use different kinds of places to ameliorate stress, reflect on personal matters, to regain and reflect on their identity?"
Korpela believes the restorative value of nature can be taught to today's stressed-out city dwellers. Under his direction, what is likely "the world's first forest trail with psychological signposts enhancing the restorative experience" was constructed recently near Ikaalinen Spa, one of Finland's largest. Hikers meander through diverse scenery and get trailside signpost instructions aimed at increasing the restorative experience: inducing reflection, relaxation and improving their moods.
Researchers will continue to quantify the amount and kind of nature we need to restore our spirits and regain our mental acuity. In the meantime, it appears Thoreau was right: "We can never have enough of nature."