I’ve
been an avid hiker my whole life. From the time I first strapped on a backpack
and headed into the Sierra Nevada Mountains, I was hooked on the experience,
loving the way being in nature cleared my mind and helped me to feel more
grounded and peaceful.
But,
even though
I’ve
always believed that hiking in
nature had many psychological benefits, I’ve never had much science to back me
up…until now, that is. Scientists are beginning to find evidence that being in
nature has a profound impact on our brains and our behavior, helping us to
reduce anxiety, brooding, and stress, and increase our attention capacity,
creativity, and our ability to connect with other people.
“People
have been discussing their profound experiences in nature for the last several
100 years—from Thoreau to John Muir to many other writers,” says researcher
David Strayer, of the University of Utah. “Now we are seeing changes in the
brain and changes in the body that suggest we are physically and mentally more
healthy when we are interacting with nature.”
While
he and other scientists may believe nature benefits our well-being, we live in a
society where people spend more and more time indoors and online—especially
children. Findings on how nature improves our brains brings added legitimacy to
the call for preserving natural spaces—both urban and wild—and for spending more
time in nature in order to lead healthier, happier, and more creative lives.
Here
are some of the ways that science is showing how being in nature affects our
brains and bodies.
1.
Being in nature decreases stress
It’s
clear that hiking—and any physical activity—can reduce stress and anxiety. But,
there’s something about being in nature that may augment those impacts.
In
one recent
experiment conducted in Japan,
participants were assigned to walk either in a forest or in an urban center
(taking walks of equal length and difficulty) while having their heart rate
variability, heart rate, and blood pressure measured. The participants also
filled out questionnaires about their moods, stress levels, and other
psychological measures.
Results
showed that those who walked in forests had significantly lower heart rates and
higher heart rate variability (indicating more relaxation and less stress), and
reported better moods and less anxiety, than those who walked in urban settings.
The researchers concluded that there’s something about being in nature that had
a beneficial effect on stress reduction, above and beyond what exercise alone
might have produced.
In
another
study, researchers in Finland found that urban dwellers who strolled for as
little as 20 minutes through an urban park or woodland reported significantly
more stress relief than those who strolled in a city center.
The
reasons for this effect are unclear; but scientists believe that we evolved to
be more relaxed in natural spaces. In a
now-classic
laboratory experiment by Roger
Ulrich of Texas A&M University and colleagues, participants who first viewed
a stress-inducing movie, and were then exposed to color/sound videotapes
depicting natural scenes, showed much quicker, more complete recovery from
stress than those who’d been exposed to videos of urban settings.
These
studies and others provide evidence that being in natural spaces— or even
just
looking
out of a window onto a natural
scene—somehow soothes us and relieves stress.
2.
Nature makes you happier and less brooding
I’ve
always found that hiking in nature makes me feel happier, and of course
decreased stress may be a big part of the reason why. But, Gregory Bratman, of
Stanford University, has found evidence that nature may impact our mood in other
ways, too.
In
one
2015 study, he and his colleagues randomly assigned 60 participants to a
50-minute walk in either a natural setting (oak woodlands) or an urban setting
(along a four-lane road). Before and after the walk, the participants were
assessed on their emotional state and on cognitive measures, such as how well
they could perform tasks requiring short-term memory. Results showed that those
who walked in nature experienced less anxiety, rumination (focused attention on
negative aspects of oneself), and negative affect, as well as more positive
emotions, in comparison to the urban walkers. They also improved their
performance on the memory tasks.
In
another study, he and his colleagues
extended these
findings by zeroing in on how
walking in nature affects rumination—which has been associated with the onset of
depression and anxiety—while also using fMRI technology to look at brain
activity. Participants who took a 90-minute walk in either a natural setting or
an urban setting had their brains scanned before and after their walks and were
surveyed on self-reported rumination levels (as well as other psychological
markers). The researchers controlled for many potential factors that might
influence rumination or brain activity—for example, physical exertion levels as
measured by heart rates and pulmonary functions.
Even
so, participants who walked in a natural setting versus an urban setting
reported decreased rumination after the walk, and they showed increased activity
in the subgenual prefrontal cortex, an area of the brain whose deactivation is
affiliated with depression and anxiety—a finding that suggests nature may have
important impacts on mood.
Bratman
believes results like these need to reach city planners and others whose
policies impact our natural spaces. “Ecosystem services are being incorporated
into decision making at all levels of public policy, land use planning, and
urban design, and it’s very important to be sure to incorporate empirical
findings from psychology into these decisions,” he says.
3.
Nature relieves attention fatigue and increases creativity.
Today,
we live with ubiquitous technology designed to constantly pull for our
attention. But many scientists believe our brains were not made for this kind of
information bombardment, and that it can lead to mental fatigue, overwhelm, and
burnout, requiring “attention restoration” to get back to a normal, healthy
state.
Strayer
is one of those researchers. He believes that being in nature restores depleted
attention circuits, which can then help us be more open to creativity and
problem-solving.
“When
you use your cell phone to talk, text, shoot photos, or whatever else you can do
with your cell phone, you’re tapping the prefrontal cortex and causing
reductions in cognitive resources,” he says.
In
a
2012 study, he
and his colleagues showed that hikers on a four-day backpacking trip could solve
significantly more puzzles requiring creativity when compared to a control group
of people waiting to take the same hike—in fact, 47 percent more. Although other
factors may account for his results—for example, the exercise or the camaraderie
of being out together—prior studies have suggested that nature itself may play
an important role.
One
in Psychological
Science found that the impact
of nature on attention restoration is what accounted for improved scores on
cognitive tests for the study participants.
This
phenomenon may be due to
differences in brain
activation when viewing natural
scenes versus more built-up scenes—even for those who normally live in an urban
environment. In a
recent
study conducted by Peter Aspinall
at Heriot-Watt University, Edinburgh, and colleagues, participants who had their
brains monitored continuously using mobile electroencephalogram (EEG) while they
walked through an urban green space had brain EEG readings indicating lower
frustration, engagement, and arousal, and higher meditation levels while in the
green area, and higher engagement levels when moving out of the green area. This
lower engagement and arousal may be what allows for attention restoration,
encouraging a more open, meditative mindset.
It’s
this kind of brain activity—sometimes referred to as “the brain default
network”—that is
tied
to creative thinking, says Strayer. He is currently repeating his earlier
2012 study with a new group of hikers and recording their EEG activity and
salivary cortisol levels before, during, and after a three-day hike. Early
analyses of EEG readings support the theory that hiking in nature seems to rest
people’s attention networks and to engage their default networks.
Strayer
and colleagues are also specifically looking at the effects of technology by
monitoring people’s EEG readings while they walk in an arboretum, either while
talking on their cell phone or not. So far, they’ve found that participants with
cell phones appear to have EEG readings consistent with attention overload, and
can recall only half as many details of the arboretum they just passed through,
compared to those who were not on a cell phone.
Though
Strayer’s findings are preliminary, they are consistent with other people’s
findings on the importance of nature to attention restoration and
creativity.
“If
you’ve been using your brain to multitask—as most of us do most of the day—and
then you set that aside and go on a walk, without all of the gadgets, you’ve let
the prefrontal cortex recover,” says Strayer. “And that’s when we see these
bursts in creativity, problem-solving, and feelings of well-being.”
4.
Nature may help you to be kind and generous
Whenever
I go to places like Yosemite or the Big Sur Coast of California, I seem to
return to my home life ready to be more kind and generous to those around
me—just ask my husband and kids! Now some new studies may shed light on why that
is.
In
a
series
of experiments published in 2014,
Juyoung Lee, GGSC director Dacher Keltner, and other researchers at the
University of California, Berkeley, studied the potential impact of nature on
the willingness to be generous, trusting, and helpful toward others, while
considering what factors might influence that relationship.
As
part of their study, the researchers exposed participants to more or less
subjectively beautiful nature scenes (whose beauty levels were rated
independently) and then observed how participants behaved playing two economics
games—the Dictator Game and the Trust Game—that measure generosity and trust,
respectively. After being exposed to the more beautiful nature scenes,
participants acted more generously and more trusting in the games than those who
saw less beautiful scenes, and the effects appeared to be due to corresponding
increases in positive emotion.
In
another part of the study, the researchers asked people to fill out a survey
about their emotions while sitting at a table where more or less beautiful
plants were placed. Afterwards, the participants were told that the experiment
was over and they could leave, but that if they wanted to they could volunteer
to make paper cranes for a relief effort program in Japan. The number of cranes
they made (or didn’t make) was used as a measure of their “prosociality” or
willingness to help.
Results
showed that the presence of more beautiful plants significantly increased the
number of cranes made by participants, and that this increase was, again,
mediated by positive emotion elicited by natural beauty. The researchers
concluded that experiencing the beauty of nature increases positive
emotion—perhaps by inspiring awe, a feeling akin to wonder, with the sense of
being part of something bigger than oneself—which then leads to prosocial
behaviors.
Support
for this theory comes from
an
experiment conducted by Paul Piff
of the University of California, Irvine, and colleagues, in which participants
staring up a grove of very tall trees for as little as one minute experienced
measurable increases in awe, and demonstrated more helpful behavior and
approached moral dilemmas more ethically, than participants who spent the same
amount of time looking up at a high building.
5.
Nature makes you “feel more alive”
With
all of these benefits to being out in nature, it’s probably no surprise that
something about nature makes us feel
more
alive and vital. Being outdoors gives us energy, makes us happier, helps us
to relieve the everyday stresses of our overscheduled lives, opens the door to
creativity, and helps us to be kind to others.
No
one knows if there is an ideal amount of nature exposure, though Strayer says
that longtime backpackers suggest a minimum of three days to really unplug from
our everyday lives. Nor can anyone say for sure how nature compares to other
forms of stress relief or attention restoration, such as sleep or meditation.
Both Strayer and Bratman say we need a lot more careful research to tease out
these effects before we come to any definitive conclusions.
Still,
the research does suggest there’s something about nature that keeps us
psychologically healthy, and that’s good to know…especially since nature is a
resource that’s free and that many of us can access by just walking outside our
door. Results like these should encourage us as a society to consider more
carefully how we preserve our wilderness spaces and our urban parks.
And
while the research may not be conclusive, Strayer is optimistic that science
will eventually catch up to what people like me have intuited all along—that
there’s something about nature that renews us, allowing us to feel better, to
think better, and to deepen our understanding of ourselves and others.
“You
can’t have centuries of people writing about this and not have something going
on,” says Strayer. “If you are constantly on a device or in front of a screen,
you’re missing out on something that’s pretty spectacular: the real world.”
This
article is printed here with permission. It originally appeared on Greater
Good, the online magazine of the Greater
Good Science Center (GGSC). Based at UC Berkeley, the GGSC
studies the psychology, sociology, and neuroscience of well-being, and teaches
skills that foster a thriving, resilient, and compassionate society. Jill
Suttie, Psy.D., is Greater Good‘s book review editor and a frequent contributor
to the magazine.
Be The Change: Find time today to get out into
nature. Soak it in with all your senses.