We already know eating your greens is vital for good health, but immersing yourself in green space might be just as important. Whether it’s a remote mountaintop or an urban oasis, green space is emerging as a powerful force for good mental health. Exposure to green space can help alleviate depression, ADHD, Alzheimer’s, and more. One particularly astounding study found that green space is nothing less than a superhero: it actually fights crime.
Here’s how that worked: 541 vacant lots in Philadelphia were randomly assigned to one of three conditions. In the first, they were “cleaned and greened,” meaning trash was removed, grass and trees were planted, and the improvements were maintained over time. In the second, lots were cleaned on a regular basis, but no greenery was planted. And in the third, the lots were left untouched. Then, the research team used police reports to track crime in the area. Near the cleaned and greened lots, crime decreased by 13%, including a decrease in gun violence almost 30%—that’s a number that should grab any civic leader by the lapels.
Why is green space so powerful? Why does it make us feel refreshed and relaxed? And how on earth does it have the power to reduce crime and violence? This week, we’ll look at a few possibilities, plus think about how to apply the answer to our lives. Okay, let’s figure this out:
First, Is Green Space Just a Stand-in for Exercise?
Maybe green space makes everybody feel better because it promotes physical activity. It is objectively more pleasant to go for a walk or a bike ride along a greenbelt than a dirty sidewalk, and a grassy field is more inviting for a soccer game than a paved lot surrounded by chain link.
But it turns out that’s not the case. A team of researchers from the Netherlands Institute for Health Services Research surveyed almost 5,000 Dutch participants about their health and exercise habits, and compared it to the amount of green space in their postal code, making sure to account for demographics and income.
Turns out there was no relationship whatsoever. In fact, people with more green space walked and cycled for leisure less, presumably because in greener, more rural environments, people needed a car to get around.
Second, Is Green Space Just a Proxy for Money?
If it’s not exercise, maybe green space is just a stand-in for socioeconomic status? Maybe greater wealth allows rich people to live in greener, more beautiful environments and afford better mental health care?
Surprisingly, that’s not the case either.
A research team from the UK tracked the mental health of almost 600 people who moved to greener areas and found that even though their income, education, employment, and household size remained pretty much the same, their mental health improved every year for the three years thereafter, with the biggest jump occurring right after the move.
If you’re still not convinced, let’s take moving out of the picture entirely. Consider another study that followed 169 low-income inner-city kids who, with their families, were randomly assigned to live in one of 12 architecturally identical high-rises. What varied was the views from their windows—some looked out on greenery, while others looked out on asphalt.
For boys, who spent less time at home, views of green space from their apartment had no effect. But for girls, who spent more time overall at home, the greener her view, the better her performance on tests of concentration, impulse control, and delay of gratification—all forms of self-discipline key to achieving long-term life goals.
So if it’s not exercise and it’s not money, what could it be?