Empirical evidence backs up what most of us already know: Being in nature is restorative and relaxing. Merely gazing out on greenery has been shown to speed recovery time for surgical patients and reduce hostility in prison inmates. Exposure to nature can also increase our capacity to concentrate and lessen stress levels. According to other studies, elderly adults whose homes are close to a park or other green space live longer. Exposure to nature is especially important to children, who benefit in a myriad of ways. Unfortunately, a recent study finds the amount of time kids spend outside declined by 50 percent between 1997 and 2003. (For 97 fun outdoor activities to share with children, download Go Play Outside).The body of evidence about the benefits of exposure to nature indicates that to function at our best --physically, mentally, intellectually-humans must be exposed to nature."Humans are evolved organisms and the environment is our habitat," said Frances Kuo, a professor of natural resources and environmental science and psychology at the University of Illinois. "Now, as human societies become more urban, we as scientists are in a position to look at humans in much the same way that those who study animal behavior have looked at animals in the wild to see the effect of a changing habitat on this species."
Speaking at the annual meeting of the American Association for the Advancement of Science recently, Kua explained that humans living in landscapes that lack trees or other natural features undergo patterns of social, psychological and physical breakdown that are strikingly similar to those observed in other animals that have been deprived of their natural habitat."In animals what you see is increases in aggression, you see disrupted parenting patterns, their social hierarchies are disrupted," she said. Kuo and her colleagues have shown that people who live in areas devoid of trees and grass suffer a variety of negative effects, including decreased civility, less supervision of children outdoors, more illegal activity, more aggression, more property crime, more loitering, more graffiti and more litter."We might call some of that 'soiling the nest,' which is not healthy," she said. "No organisms do that when they're in good shape."Certain psychological problems are also likely to appear more often in those lacking access to nature, she said."In our studies, people with less access to nature show relatively poor attention or cognitive function, poor management of major life issues, poor impulse control," she said.
Other researchers have found that access to nature positively influences a person's mood, life and work satisfaction, she said.
Kuo has seen such psychological effects in children with ADHD. In a 2001 study, she and her colleagues asked parents of children with ADHD which after-school activities worsened - and which soothed - their children's symptoms. The parents consistently reported that outdoor activities in natural settings lessened their children's ADHD symptoms more than activities conducted indoors, or in built environments outdoors.
In a 2008 study, Kuo and a colleague, Illinois postdoctoral researcher Andrea Faber Taylor, studied children with ADHD who went on field trips in green or manmade environments. After the trips, other researchers (who didn't know where the kids had been) tested their concentration. Children with ADHD had significantly better concentration after a walk in a park than in an urban setting. The difference was comparable to what is achieved with standard ADHD medication, Kuo said, although "no one knows how long the green effect will last."
More recent studies by various teams in Japan, the Netherlands, the United Kingdom and the U.S., are showing that access to nature - or lack thereof - can also have significant physical effects. A large-scale study in the Netherlands found that general health is predicted by the amount of green space within a 1-mile or 3-mile radius, Kuo said. Another study found that elderly Japanese adults lived longer when their homes were within walking distance of a park or other green space. These effects were independent of their social or economic status.
While none of these studies proves conclusively that nature is essential to optimal functioning in humans, Kuo said, the body of evidence strongly points in that direction."So when people say: 'As a scientist, would you say that we know this now? Do we know that people need nature?' I say: 'As a scientist I can't tell you. I'm not ready to say that,' " Kuo said. " 'But as a mother who knows the scientificliterature, I would say, yes.' " Grandparents.com offers a free download with 97 fun outdoor activities you can share with kids. Download Go Play Outside.