Parks and Gardens are also essential to human social and psycological well-being. Without access to grass and trees, says Frances Kuo, we humans are very different creatures. For the past decade, Kuo and her colleagues at the Landscape and Human Halth Laboratory of lthe University of Illinios have researched the effects of green space on city dwellers. The team carries out many of its studies in Chicago’s public housing neighbourhoods, where barren expanses of hardscape reflect the old view that vegetation is an extravagence the city can,t afford.
One sequence of studies focussed on residents of the Robert Taylor Homes, a cluster of 28 identical high rise buildings, now mostly torn down that formed the nation’s largest publilc housing development. Some of the buildings were surrounded by grass and trees, others by concrete and asphalt, Kuo and her team discovered that people living in buildings near green areas had a stronger sense of community and cooped better with everyday stress and hardship. They were less aggressive and less violent, they performed better on tests of concentration, they managed their problems more effectively.
They also felt safer—and with good reason. In one of its more startling findings, the team upended the common belief that barren spaces are safer than green ones. A study of violent crime in a housing project of 98 apartment buildings showed that in and around buildings near vegetation that didn’t hamper visibility there were only half as many crimes as in areas near no vegetation. The greener the surroundings, says Kuo, the lower the crime rate against people and property. The team also found less litter and graffiti in natural landscapes.
In their most recent research, a national study of 450 children ages five to eighteen, the scientists discovered that children with attention deficit disorders showed reduced symptoms when they were exposed to natural environments. After play in verdant settings, parents reported that the childrens ability to concentrate, complete tasks and follow directions improved dramatically – in all age groups, in all parts of the country.
Why would vegetation influence our mental well-being ? For one thing, grass and trees provide a welcoming place for people to gather. In hectic and crowded cores of cities, people need the little grove of chestnut trees outside their apartments where they can mingle in the shade and hear the hiss of wind in high trees. They need big public lawns where they can play together. They need tiny sprouting plots of neighbourhood gardens, where they can put aside the citys stress on time and the temporary in favour of growth and permanence.
Scientists suspect tht green space also has a restrorative effect on our voluntary attention, the kind of intense focus required to work or study, to ignore distractions and concentrate on the task at hand. Voluntry attention is like a mental muscle; we exercise it in nearly every aspect of our lives. It dictates how well we think and how we handle ourselces in difficult situations – whether we roll with the punches or fly off the handle. Living in a city with its relentless crush of noise and traffic, conflicts and demands, makes us “crabby and impulsive,” says Kuo Being in nature refreshes us by letting us give voluntary attention a rest and allowing us to surrender to involuntary attention: the effortless and often enjoyable noticing of sensory stimuli in our environment.
Kuo speculates that over the course of human evolution, there was selection for this response to the natural world. Our ancestors who found nature effortlessly engaging had an advantage. “They were the ones more likely to know where the berries could be found and where the critters hung out,” she says. “When push came to shove in difficult environmental conditions, they were better able to survive.”
In our modern era, with all its pressures, contact with nature in urban settings may be more crucial than ever. A park rich metropolis helps us stay physically healthy and battle overweight and diabetes. Two big recent studies of people in populated urban centres in the Netherlands and Japan showed that those living in areas with easy access to green spaces where they could walk ahd significantly better health and lower mortality rates than those without. Health studies suggest that even relatively passive contact with nature lowers blood pressure and anxiety levels.
(c) National Geographic Magazine 10/06