[Cross-posted at the Earth Forum]
To many individuals, it seems intuitively obvious that communion with nature is beneficial to body and soul. Two decades ago E.O. Wilson memorably articulated this association as biophilia — humans’ “innate tendency to focus on life and lifelike process.” He argued that “To an extent still undervalued in philosophy and religion, our existence depends on this propensity, our spirit is woven from it, hopes rise on its currents.”
This is a pretty bold claim. But while Wilson’s argument for biophilia is primarily poetic and personal, there is also some intriguing scientific evidence consistent with it. Some years ago, researchers famously showed that hospital patients recovered more quickly and needed less pain relief when their rooms looked out on trees compared with brick walls. And subsequent studies have shown that the availability of “greenspace” (parks and areas of vegetation within urban areas) enhances various measures of human well-being — including general health, social interaction, recovery from mental fatigue, and opportunities for reflection.
Although these benefits of greenspace are now widely recognized, the association usually has been considered in a fairly generic way. But all greenspaces are, of course, not created equal. In a fascinating new research paper, Richard Fuller and colleagues show for the first time that the psychological benefits of greenspace increase with the biological diversity of that space. The team used standard ecological techniques to measure diversity of plants, butterflies, and birds in 15 urban greenspaces in the English city of Sheffield. Then they interviewed 312 people strolling through the parks about their feelings of psychological well-being, using standard approaches based in psychology and social science research. The questions involved reflection (ability to think and gain perspective), distinct identity (feelings of uniqueness or difference associated with a particular place), continuity with the past (sense of identity across time), and attachment (emotional ties with the greenspace). Finally, they also asked the strollers about their perceptions of species diversity within the parks.
In a nutshell, the researchers found that several psychological benefits increase with diversity (number of species) within the greenspaces. Specifically, reflection and perceptions of identity both increased with the diversity of plants in the space and – surprisingly – this positive influence of diversity was stronger than the expected effect of greenspace area. In other words, people’s sense of well-being was more affected by the variety of the vegetation than by park size. Similarly, the park users’ feelings of attachment and continuity with the past were greater in areas with more species of birds present (perhaps harking back to those idyllic days of childhood filled with birdsong). Finally, the interviewees’ perceptions of plant and bird diversity within the parks reflected the scientifically measured species diversity more or less accurately, showing that regular folks strolling through the park indeed had a good intuitive sense of the biodiversity therein.
The new study provides some quantitative data that corroborates what many nature-lovers, hunters, and fisherfolk already sensed intuitively, and supports Wilson’s concept of biophilia, that is, that maintaining a variety of living things around us does a body (and mind) good. And they didn’t even have to climb the mountain to ask the wise man the secret of inner peace!
[Photo is from Central Park, New York City]