Researchers have been studying the relationship between mental health and urban green space for years, but they haven’t always been able to make a causal connection between the two.
Now, a new study from researchers at the European Centre for Environment and Human Health at the University of Exeter Medical School shows that moving from a less-green urban environment to a more-green one can lead to lasting positive changes in mental well-being.
Human happiness is a slippery thing, and figuring out how to increase it is notoriously difficult. In the 1970s, a theory known as the "hedonic set-point" or, even more depressingly, the "hedonic treadmill," gained traction in the field of psychology. It posits that every person has a baseline level of happiness, and that while satisfaction may rise and fall temporarily along with life events such as winning the lottery or getting divorced, it will generally return to the same level, largely determined by genetics.
It's a rather grim vision, especially if you're not a "naturally" happy person. But it has been challenged in recent years. Some happiness researchers believe that "well-being set points can change under some conditions." This latest study, which followed 1,000 subjects over a five-year period using data from the British Household Panel Survey, suggests that an increase in the green space in a person’s surroundings might be one of those conditions.
Ian Alcock, one of the researchers on the green-space study, summarized his group’s findings this way in the above video: "When people move to a greener urban area, they experience an immediate and sustained improvement in their mental health," he says. He notes that the observed effect differs from the quick but transient boost that, say, getting married can deliver. "Their mental health improves straightaway, and that improvement endures, at least for the three years that we were able to follow them."
Interestingly, the mental health of people moving from more-green to less-green areas sustained a drop in the time before the move, then returned to what was normal for them.
The researchers believe that their findings have direct implications for urban planners and investment in green space. "It suggests that new parks and urban corridors might have long-term benefits for communities," says Alcock.
In other words, building a park or garden won't just give a cheap honeymoon thrill to a city or town. Instead, it will keep delivering mental health faithfully for years to come.