Green is good for you
Psychologists’ research explains the mental and physical restoration we get from nature–and has important implications for how we build our homes, work environments and cities.
By REBECCA A. CLAY April 2001, Vol 32, No. 4, 9 min read
When psychologist Rachel Kaplan, PhD, switched offices at the University of Michigan in Ann Arbor, she was only a little surprised by how good she felt in the new space. The office where she had spent the past 17 years looked out on a barren wall in a courtyard whose sole tree had long since been removed. Her new office offers a tree-top view.
As Kaplan works at her computer or chats on the phone, she can now gaze out at trees and watch the birds and squirrels as they leap from branch to branch. The effect these sights have had on her outlook only confirms what she and husband Stephen Kaplan, PhD, have found over decades of research: Green is good for you.
“My previous office was harder on me than I realized,” says Kaplan, a professor of psychology and the Samuel T. Dana professor of environment and behavior in the School of Natural Resources and Environment. “I have to admit I was more convinced of my own work after I changed offices. I realized that all of our results were right.”
The Kaplans are at the forefront of research on what they call “restorative environments.” They and other psychologists are exploring nature’s impact on people’s mental functioning, social relationships and even physical well-being. Others are putting that research into practice by working with interior designers, architects and city planners to create psychologically healthy buildings and cities.
Restoring mental clarity
The Kaplans didn’t start out with a professional interest in nature. Back in the 1970s, USDA Forest Service funding pulled them into research on the effects of an outdoor challenge program in a wilderness setting in Michigan’s Upper Peninsula. That was the beginning of a series of investigations with findings that have influenced a generation of environmental psychologists.
“What we found was incredibly impressive,” says Stephen Kaplan, a professor in the departments of psychology and computer science and engineering at Michigan. “That wilderness became a laboratory for studying nature’s effect on people.”
What grew out of that work was the influential theory of restorative environments outlined in such books as “With People in Mind: Design and Management for Everyday Nature” (Island Press, 1998). Drawing on William James’s distinction, between two kinds of attention, which they refer to as directed attention and fascination, the Kaplans argue that using too much of the former can lead to what they call “directed attention fatigue” and the impulsivity, distractibility and irritability that accompany it. The inherent fascination of nature can help people recover from this state.
“Directed attention fatigues people through overuse,” Stephen Kaplan explains. “If you can find an environment where the attention is automatic, you allow directed attention to rest. And that means an environment that’s strong on fascination.”People don’t have to head for the woods to enjoy nature’s restorative effects, the Kaplans emphasize. Even a glimpse of nature from a window helps. In one well-known study, for instance, Rachel Kaplan found that office workers with a view of nature liked their jobs more, enjoyed better health and reported greater life satisfaction.
Terry A. Hartig, PhD, MPH, is one psychologist who draws on the Kaplans’ work in his own research. In a series of lab and field experiments, he has explored nature’s ability to help people recover from what he calls “normal psychological wear and tear.”
In one study, for instance, he asked participants to complete a 40-minute sequence of stroop and binary classification tasks designed to exhaust their directed attention capacity. After the attentionally fatiguing tasks, the randomly assigned participants spent 40 minutes walking in a local nature preserve, walking in an urban area, or sitting quietly while reading magazines and listening to music. After this period, those who had walked in the nature preserve performed better than the other participants on a standard proofreading task. They also reported more positive emotions and less anger.
“These are not spectacular natural environments or horribly oppressive urban environments,” says Hartig, an associate professor of applied psychology at the Institute for Housing and Urban Research at Uppsala University in Gävle, Sweden. “We try to represent typical local conditions, using what’s available to people in the way of places they can enter if they’re feeling stressed and want some relief.”
Even when represented with brief photographic simulations, local natural and urban comparison conditions can have differential effects, says Hartig, an avid hiker and climber who finds restoration in the Sierra Nevada range of California. In one study, he showed people photographs of a forested area and downtown Stockholm and found that the forest slides boosted people’s mood.
Frances E. Kuo, PhD, is also busy testing nature’s impact on people. In her case, the goal is to determine whether nature can help mitigate the negative impact of living in bleak, urban environments. Instead of heading to the wilderness, she conducts most of her research at the notorious Robert Taylor Homes–the country’s largest public housing project–in Chicago.
“The ‘green’ landscapes in these studies are not what most people would call green,” says Kuo, co-director of the HumanEnvironment Research Laboratory at the University of Illinois at UrbanaChampaign. “We’re talking about isolated pockets of green containing just the bare bones of grass and a tree.”
That limited amount of nature nonetheless has a marked impact on children living nearby, says Kuo. To test her theories, she puts children through a battery of tests and then compares the performance of children living in buildings near a green spot and those living in buildings surrounded by barren concrete. Children who live in greener environments have greater capacity for paying attention, says Kuo, and they’re better able to delay gratification and inhibit impulses.
Kuo has also examined nature’s impact on children with attention deficit-hyperactivity disorder in middle-class settings. Parents reported that their children exhibited fewer symptoms after spending time in green surroundings than when they pursued activities indoors or in non-green outdoor areas.”You could say that the kids who had greener settings were just richer,” says Kuo. “But that doesn’t explain the fact that even rich kids do better after green settings than after brown settings.”
Healing the body
Nature doesn’t just have an effect on the mind. Roger S. Ulrich, PhD, director of the Center for Health Systems and Design at Texas A&M University, has found that nature can help the body heal, too.In his most well-known study, Ulrich investigated the effect that views from windows had on patients recovering from abdominal surgery. He discovered that patients whose hospital rooms overlooked trees had an easier time recovering than those whose rooms overlooked brick walls. Patients able to see nature got out of the hospital faster, had fewer complications and required less pain medication than those forced to stare at a wall.
Like other researchers, Ulrich has found that simply viewing representations of nature can help. In a study at a Swedish hospital, for instance, he found that heart surgery patients in intensive care units could reduce their anxiety and need for pain medication by looking at pictures depicting trees and water.
These and other findings form the basis of Ulrich’s theory of supportive design, a series of guidelines for designers of health-care facilities. To soothe patients, families and employees, he says, facilities should incorporate such features as nature views and nature-related art in patients’ rooms, aquariums in waiting areas, atria with greenery and fountains and gardens where patients, family and staff can find relief.Of course, what people see isn’t the only aspect of the environment that has an impact. Gary W. Evans, PhD, a professor of human-environment relations at Cornell University, studies the effect of noise pollution.
“One of the interesting things about work on restorative environments is to think about the question of restored from what?” says Evans.Evans has found that noisy environments have effects that go beyond hearing damage. In a study of first- and second-graders, for instance, he found that children attending a school with airplanes flying overhead scored 20 percent lower on word recognition tests.
Even small amounts of noise can be harmful. Evans has found that clerical workers exposed to conversation and other mild office noise showed higher stress levels and gave up on performance tests faster than those with quiet offices did.
City planners, architects and others need to pay more attention to this and other research from environmental psychologists, says Evans.
“Architects think of themselves as sculptors and see what they’re doing as leaving their signature on the landscape,” he notes. “But architecture has profound implications for human health and behavior.”
Designing with nature in mind
Joseph B. Juhasz, PhD, president-elect of APA’s Div. 34 (Population and Environmental), agrees. In fact, he believes that one explanation for the current epidemic of depression lies in the near-universal experience of uprootedness and alienation fostered by the environments in which we live.
“What we desperately need is connection with our blood and soil,” says Juhasz, a professor of architecture and environmental design at the University of Colorado in Boulder. “We’re estranged from our blood–ourselves as human beings, and our soil, our natural environment–at this moment in our culture.”
Juhasz has proposed a solution in numerous design competitions: high-density cities that are long and thin instead of round and fat, giving all inhabitants easy access to the surrounding countryside.
Psychologist Judith H. Heerwagen, PhD, is already putting the principles of restorative environments into practice in the work she does as a consultant to designers, companies and others.
Heerwagen began her career studying animal behavior. Gradually her interest shifted to how humans’ prehistoric experiences on the African savanna shape their environmental preferences. Now she’s trying to find ways to make people more psychologically comfortable by “naturalizing” interiors.
To achieve that goal, Heerwagen is working with designers to take natural patterns and render them in abstract ways suitable for interiors. For example, she replaces bold geometrics with abstracted natural patterns in floor-coverings and uses branch-like forms overhead to make ceilings reminiscent of tree canopies. In an upcoming experiment, Heerwagen will test whether these abstracted forms of nature have the same impact on people as nature itself.
“Once you start thinking about it, this kind of design makes perfect sense,” says Heerwagen, principal of J.H. Heerwagen and Associates and senior scientist at the Pacific Northwest National Laboratory in Seattle. “We didn’t evolve in a sea of gray cubicles.”
Rebecca A. Clay is a writer in Washington, D.C.