Countless studies have found that spending time in nature is good for mental health. But these studies might not have the whole story.
According to a review published last week in Current research in environmental sustainability, the researchers analyzed ten years of major studies on how nature affects well-being. Ninety-seven percent, according to the study, came from wealthy countries. The authors argue that this bias limits the universality of fashionable ideas about the healing power of green spaces.
“A giant proportion of humanity is not included,” said Rachelle Gould, one of the authors. Reverse. “And so we can’t tell what’s universal and what’s culturally specific.” Gould, a professor of environmental studies at the University of Vermont, sees the gap as a barrier to his field “to impact the world, to improve human well-being in a sustainable way.”
And, according to the authors of the new study, when nature research comes from wealthy, Westernized countries, Western ideas about the purpose of nature are promoted and others ignored.
How they did it — The researchers scoured academic literature databases for nature and mental health studies published from 2010 to 2020, expanding their network using several synonyms related to the two concepts (well-being, stress, anxiety , etc.; outdoor, environment, wood, etc.) .
What’s new – They found 174 peer-reviewed studies. Ninety-seven percent were conducted in countries classified as high income by the World Bank, 2.9 in upper middle income countries, 1.1 in lower middle income countries. (These are two studies, one from India and the other from Iran.) None were from low-income countries.
Of the 217 countries indexed by the World Bank, 80 are high income, 55 upper middle income, 55 lower middle income and 27 low income. “[T]there is therefore a monumental under-representation”, indicates the study, “mainly from countries of the Global South”.
The overrepresentation of the richest countries should co-align with an overrepresentation of Western countries. Seventy-five percent of the studies were conducted in the Western Hemisphere. Another 23.3% came from countries considered westernized by at least one of the two indexes commonly cited by researchers. These are places that, regardless of the continent, have adopted essential Western values or ways of life. They include China, South Korea, Singapore, Israel and South Africa.
Studies in places like China have tended to focus on urban centers, not agricultural populations, for whom nature is no temporary refuge. “These studies take place in relatively large cities, globalized cities,” explains Carlos Andres Gallegos-Riofrío, another co-author. “When you read these studies, they basically replicate the formula of studies done in the western world. There is no cultural nuance, not even for their own diversities.
This means that 98.3% of environmental and mental well-being data from westernized countries and large swathes of the global map are not represented. Only one study per region was conducted in Latin America, South Asia and Africa, and only two in the Middle East. Meanwhile, 30 have been conducted in the United States and 11 in Canada.
Bias in study participants is an increasingly recognized problem in psychology in general. Scholars, especially those who publish in top journals, are more likely to study Westerners, affluent and educated people, and those who live in stable democracies. Yet the results are often applied universally.
One reason is logistics. These are the populations to which psychologists have the easiest access. Additionally, says Gould, psychology tends to attract more scholars in Westernized countries because it is “very much focused on the individual mind, and the mentality aligns more with Western and American thinking.”
Another common diversity issue in the 174 studies the researchers collected was that they were largely indifferent to racial differences within their study samples. Only 62% reported their ethnicity, and in studies that tracked ethnicity, “white participants are significantly overrepresented, especially when compared to national demographic breakdowns,” the new paper says.
Why is it important – In an age that is overloaded, overconnected, and obsessed with non-pharmacological ways to live better, nature therapy is all the rage. There is a cottage industry of pop psychology books extolling the mental health benefits of dating, with titles like Your brain on nature. Well maintained mind, The natural health service, The natural remedyand Ecotherapy. (Two books, one from 2009 and another from 2016, share the latter title.)
A broader approach is unlikely to reverse the overall message of these books and reveal that nature is actually good for your well-being. However, the paper’s authors argue that an overrepresentation of wealthy, white populations threatens to erase some cultures’ unique relationships with green spaces.
“Nature is treated as a mechanism to relieve mental distress and improve cognitive functions, rather than as an intertwined, sacred and fundamentally holistic entity.”
“An example in the United States that’s really relevant is that there’s a lot of talk about African Americans, the black community, having a different relationship with the forest than white people,” Gould says.
Several studies have shown that black Americans are less likely to engage in nature-based hobbies. Cassandra Y. Johnson, one of the first sociologists to study divide, once wrote that “collective black ‘memory’ of sociohistorical factors such as slavery, sharecropping/Jim Crow and lynching may have contributed to a black aversion to wild environments.”
Indigenous peoples are another group that has a fundamentally different view of nature. They were almost completely absent from the studies reviewed by the researchers. Only two studies, one from Canada and one from New Zealand, included participants who explicitly marked their identity as Aboriginal, and these were less than 10% in each.
Gallegos-Riofrío studies Andean states – the part of South America clustered around the Andes, including Bolivia, Chile, Ecuador and Peru – where indigenous peoples make up a significant percentage of the population.
This First Nation of the Andean States defended “the rights of nature”, the idea that the natural world is a legal entity endowed with rights and protections (codified in the Ecuadorian constitution). They have different self-conceptions, says Gallegos-Riofrío; the Quechua language does not have unique words for “I” and “we”. This renders Western mental illness assessment tools useless, he says.
How would a discovery, such as, say, that horticulture alleviates the symptoms of depression, apply to them?
The paper’s authors also noted that the research they were evaluating often had a Westernized definition of “nature” as a resource to use.
From the study:
Our assessment demonstrates that research in this field overwhelmingly considers nature as a therapeutic alternative: “natural doses” are health interventions, wilderness is therapy and “vitamin G” (green spaces) is a “substance” that humans need. Nature is treated as a mechanism to relieve mental distress and improve cognitive function, rather than as an intertwined, sacred, and fundamentally holistic entity.
Studies have tended to focus on parks, the institutionalized green spaces that exist in highly industrialized countries. They rarely defined nature as a “place not separate from humans and not as a commodity that can be possessed, but as a spiritual relationship that sustains life.”
The document lists a number of remedies: try to reach unrepresented subsets of people; record the ethnicities of study participants; and “create a repertoire of culturally sensitive instruments, tools and designs” to measure mental health and connection to nature.
“It really matters,” says Gould. “There is something truly powerful in nature, and let’s make sure we understand what it is, in all its facets.”