There's plenty of evidence for the idea that humans thrive when we have frequent exposure to nature—even when it's just a patch of greenery in the midst of a city's concrete jungle.
Studies have found that, after looking at nature scenes, people are kinder and more charitable. They've suggested that children with ADHD have an easier time concentrating when they spend time outdoors. A 2008 study even found that, for office workers, a mere glimpse of green through a window or a live plant on their desk were, on the whole, associated with lower stress levels and higher job satisfaction.
A new study published last week in Environmental Science & Technology underscores just how important green spaces are for our long-term well-being. When a group of researchers from the UK's University of Exeter looked at five years' worth of mental health data for 1064 participants who moved their residence during the study period, they found that those who moved to urban areas with more surrounding green space showed higher overall mental health scores—meaning that they were happier and had lower levels of anxiety and depression—for the very first year after their relocation compared to the years prior to moving.
Even more important, they found that these benefits lingered. Participants who'd moved to greener areas showed higher mental health scores for a full three years after their relocation, when the study stopped collecting data.
The data came from the British Household Panel Survey, a project started by Exeter researchers in 1991 that annually collects information on all sorts of socioeconomic trends from thousands of British households. By parsing the data, the researchers found 594 households that moved to urban areas with more green space, and 470 households that moved into parts of cities with less of it, based on residence addresses collected in the survey and databases of green space in England.
To guage mental health, the researchers analyzed the answers provided by the people in response to questions like "How much stress have you felt in the past few weeks compared to usual?" or "How hard has it been for you to concentrate in the past few weeks compared to usual?" Responses were collected periodically over the next few years.
After running statistical regressions to eliminate the influence of confounding factors such as income, employment, education and personality traits, they found that for three full years after their move, people in greener areas showed markedly better mental health scores compared to the two years prior to moving. This is a metric that not only includes stress levels and the ability to concentrate, but also the ability to make good decisions, a person's level of confidence, overall happiness and other factors.
Interestingly, people who moved in the opposite direction—from greener to less green areas—showed the opposite effect, but for unclear reasons, it happened in the year prior to relocation. After moving, their overall mental health metrics returned to baseline levels, perhaps indicating that they moved because of a dissatisfaction with other elements of their lifestyle.
Regardless, the fact that people who moved to greener spaces experienced a bump in mental health that stuck around for years afterward is an important finding. As the Atlantic Cities points out, some psychologists believe that, regardless of circumstances, most of us have a baseline level of happiness regardless of our circumstances, a theory called the hedonic treadmill. We might briefly become happier due to various factors (like moving to a greener area), the thinking goes, but the thinking goes that ultimately we'll return to the same innate level of mental health and satisfaction we'd have had otherwise.
But the new study suggests something different—that, when it comes to the level of nature and green space in our immediate surroundings, we can become happier in a long-term, durable way. If you move next to a park, the benefit for your mental health isn't a novelty that goes away, but something that sticks around for years.
This is meaningful for people deciding where they might relocate next, but it's also significant on a much broader level too. "These findings are important for urban planners thinking about introducing new green spaces to our towns and cities, suggesting they could provide long term and sustained benefits for local communities," Ian Alcock, the study's lead author, said in a press statement.