December 2019 - Parks & Recreation - 33

" In cities, big green spaces are
very important for people's sense
of well-being, " says Schwartz. This
means that efforts to protect and
expand urban natural areas extend
far beyond luxury and secondtier concerns. According to Taylor
Ricketts, a co-author of the new
study and director of the Gund
Institute for Environment, " We're
seeing more and more evidence
that it's central to promoting mental health. "
In recent years, " a big focus in
conservation has been on monetary benefits - like how many
dollars of flood damage did we
avoid by restoring a wetland? "
Ricketts says. " But this study is
part of a new wave of research
that expands beyond monetary
benefits to quantify the direct
health benefits of nature. What's
even more innovative here is our
focus on mental health benefits -
which have been really underappreciated and understudied. "

Measuring Happiness
The hedonometer, an online instrument, has been gathering and
analyzing billions of tweets for
more than a decade. It was invented by a team of scientists at UVM
and The MITRE Corporation, including Chris Danforth and Peter
Dodds, professors at the Vermont
Complex Systems Center and
co-authors on the new study. The
instrument uses a body of about
10,000 common words that have
been scored by a large pool of volunteers for what the scientists call
their " psychological valence, " a
method for measuring each word's
emotional temperature.
The words the volunteers perceived as the happiest ranked near

the top of a 1-9 scale; sad words
near the bottom: " happy " ranked
8.30, " hahaha " 7.94 and " parks "
7.14. Truly neutral words, such as
" and " and " the, " scored 5.22 and
4.98, respectively. At the bottom,
" trapped " 3.08, " crash " 2.60 and
" jail " 1.76. " Flowers " scored a
pleasant 7.56. Using these scores,
the team collects nearly 50 million
tweets each day. " Then we, basically, toss the words into a huge bucket, " says Dodds, " and calculate the
bucket's average happiness score. "

Park Position

The Cause of Affect

To devise the new study, the scientists gathered tweets from 4,688
users whose locations were geotagged with latitude and longitude
in the city of San Francisco. " Then,
working with the U.S. Forest Service, we developed some new techniques for mapping vegetation of
urban areas - at a very detailed
resolution, about a thousand times
more detailed than existing methods, " says Jarlath O'Neil-Dunne,
director of UVM's Spatial Analysis
Laboratory and a co-author of the
new study. " That's what really enabled us to get an accurate understanding of how the greenness and
vegetation of these urban areas [relate] to people's sentiment there. "
" This is the first study that uses
Twitter to examine how user sentiment changes before, during
and after visits to different types
of parks, " says Schwartz, whose
work is supported by the National
Science Foundation. " The greener parks show a bigger boost. "
Overall, the tweets posted from
these urban San Francisco parks
were happier by a dramatic 0.23
points on the hedonometer scale
over the baseline.

" While we don't address causality
in our study, we do find that negative language - like 'not,' 'no,'
'don't,' 'can't' - decreased in the
period immediately after visits to
urban parks, " says Danforth, " offering specific linguistic markers
of the mood boost available outside. " Conversely, the study shows
that the use of first-person pronouns - " I " and " me " - drops
off dramatically in parks, perhaps
indicating " a shift from individual to collective mental frame, " the
scientists add.
For centuries, thinkers have
wondered about the sources of
happiness, and, for decades, psychologists have studied how to
promote it, but this new study supports one fundamental insight: In
nature, people tend to be happier.
" That's a finding that may help public health officials and governments
make plans and investments, " says
researcher Aaron Schwartz - and
help you feel good about heading
for the park.
Joshua Brown is a Science Writer whose work has appeared in
the Boston Globe, U.S. News & World Report and Conservation.
He writes and teaches environmental journalism at the
University of Vermont (joshua.brown@uvm.edu).

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December 2019 - Parks & Recreation

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