In 2015, sixty participants were assigned to a walk in either the city or a park in Stanford. They weren’t told why - instead, they were instructed to take ten pictures of whatever caught their attention during their walk.
50 minutes later, they sat down to take a round of tests measuring everything from their feelings to attention spans. The researchers then matched these against a previous set of results completed earlier that day.
Park walkers were less anxious, did less overthinking, and were just happier, confirming a pretty widely documented effect from spending time in nature.
We spend 90% of our lives inside a building, and scientists are increasingly asking whether less exposure to nature is degrading our mental health.
Most people agree that spending time in nature helps us, but in general I’ve found advice on this to be vague and scattered. Here’s an attempt to summarize the research on this topic in one place.
Great, but what’s actually going on here?
Let’s start by listing out the benefits we’re pretty sure about.
Window views help well-being, job satisfaction, and even reduce the amount of painkillers hospital patients need.
Living next to a green area leads to lower levels of overall stress and better mental health in general. Children in natural areas have higher cognitive function and better self-esteem, while their parents were also less stressed.
Exposure to nature helps improve depressive symptoms - even therapy is more effective in green spaces.
There is some evidence that attention and working memory gets better after spending time in nature (or even just looking at pictures) - also linked to better problem solving and creativity.
People feel better doing “green exercise”. The same activity done in a park versus a gym results in more energy, less anxiety, and less tiredness.
Is there an optimal dose?
Reviewers found the biggest spike in effects after either 5 minutes or a whole day of green exercise - just starting gives many benefits, and the mood benefits are actually bigger for light activity. Regular, short activity in nearby green spaces seems to be the best way to go (think lunchtime walk in the park).
On the other hand, a lot of benefits are over the long-term. Regular outdoor play for children has physical and mental health benefits, and since simply living near a green space makes a difference, they raise important questions about how we design our cities and living environments.
Why does this happen?
The explanations are much less convincing than the effects we have.
This is partly because many studies don’t set the same boundaries when testing hypotheses - for example, how do you quantify how “green” somewhere is?
Even so, we’ll quickly go through two of the most popular explanations: Stress Reduction Theory (SRT) and Attention Restoration Theory (ART).
SRT says that natural areas are subconsciously seen as safe havens. Since we’ve evolved to be happier in areas with greater survival rates (water/plants), we naturally become less stressed.
ART says that living in the city overloads our attention system. Nature replenishes our directed attention capabilities by giving them a chance to relax.
There’s plenty of overlap here, and you can also have a crossover in ideas like: does reducing stress help you concentrate better, or is it the other way around? The main difference between these two is that SRT is more about your nervous system - cortisol, blood pressure, heart rate - while ART is about your “cognitive system - how well you solve problems and remember things.
Both theories have a lot of different explanations, mostly along the lines of “we’ve evolved to like these things.” These are still vague and mostly unproven, although they intuitively make sense. Some scientists speculate that ART comes from fascination with nature, but that seems less likely since most studies show that places with less biodiversity still have the same effect.
What do I do?
Being a city person, I was surprised at both the range of effects and amount of research people have done on this topic. Although we’re still not exactly sure why, there’s a clear message to spend more time around nature if you can.
Funnily enough, there’s also a flip side to this: what if you get scared of being attacked by wildlife, or caught in a natural disaster? There hasn’t been as much done in this area, so for now stick with your local park rather than the Amazon jungle.
Thanks for reading! As usual, some useful sources are linked below if you’re interested in further reading.
2022, Journal Impact Factor - 4.6
Nature's broken path to restoration. A critical look at Attention Restoration Theory - ScienceDirect
2018, Journal Impact Factor - 5.2
2012, Journal Impact Factor - 5.2
The benefits of nature experience: Improved affect and cognition - ScienceDirect
2015, Journal Impact Factor - 5.1
2012, Journal Impact Factor - 3.8
2010, Journal Impact Factor - 11.4