Urban Realities Laboratory, University of Waterloo, Canada
There’s no shortage of research suggesting that cities can be bad for our mental health. The incidence of depression and psychosis is higher in cities, and though the reasons for this are not yet completely worked out, some simple explanations such as exposure to toxins and pollutants that might be found in greater abundance in cities have been more or less ruled out—most of the clues point to more psychological explanations for the malaise that some experience in dense urban environments. Some studies have suggested that the stresses that arise in dense settings may be to blame for producing psychopathologies in vulnerable individuals, and some have pointed to the problems of loneliness and isolation that can arise in cities. City dwellers have to contend with the general problem of living among thousands of strangers, and considered across the broad sweep of human history, this is a recent turn of events and one for which we are not necessarily neurologically equipped. Early humans, like the more social of our primate cousins, would have lived in small groups where everyone knew everyone and could see and understand what was happening in their small social circle most of the time.
Urban design can exert a strong influence on our patterns of behaviour and our stress levels. Both the anonymity of life in a high-rise and the isolation of automobile-centric suburban life can exact a heavy toll on urban residents. Astonishingly, a recent survey showed that one-third of Americans have never interacted with the people who live next-door to them.
But it isn’t just the maladaptive social pressures exerted on us by city environments that cause undue stress and challenges to our well-being. What some might think of as the simple aesthetic of an urban environment—the look and feel of a neighbourhood—also produces a measurable effect on our mental health. One simple and now well-studied example has to do with natural environments. We no longer think of a city’s green-space as an aesthetic bauble or as the “dessert” of city planning that should be parachuted into place as an afterthought. In the past, all too often, public places with natural landscapes were squeezed into a setting wherever they could be afforded and made to work. Now, entire urban landscapes are being dramatically transformed by the careful planning of park areas. For examples of this, one need only look at the Millennium Park Project in Chicago or the spectacular Highline in New York City. Along with the overwhelmingly positive public response to such spaces, there is plenty of hard-nosed science suggesting that exposure to scenes of nature, even very modest ones, can have a dramatic impact on public health. In one recent study, a link was made between the density of urban trees on boulevards and a host of public health variables including rates of heart disease and diabetes.
Beyond the well-documented restorative effects of green-spaces, we showed that many aspects of the urban surround can exert a strong effect on our moods, our levels of arousal, and our attraction to particular areas of the city. For example, we showed that long, unbroken, featureless facades cause passersby to become unhappy, bored, and perhaps even a little angry. In our studies of urban psychogeography in Mumbai, we discovered that in a hyper-dense city, respite from the crowding and noise of city streets in an empty place (like a quiet churchyard) can produce as much psychological restoration as a refreshing oasis of green might do in a less dense environment. We’ve also been able to show that although different types of green-spaces might have entirely different contexts and meanings (cemeteries, community gardens, traditional parks) all can produce a profound health-giving restorative response. Although we don’t yet know how these fleeting changes in thoughts and feelings that correlate with our movements through a city might translate into long-term health measures, it would be surprising if there weren’t such connections, and the current work in our laboratory is devoted to finding them.
There has never been a more pressing time for us to understand the psychological impact of urban development on the human brain.
More than half of the world’s population now live in large cities, and the construction of hyper-dense cores is taxing the abilities of city planners to provide the infrastructure that is needed to provide services and transportation to those who live and work in these dense clusters. But just as important as such bread-and-butter concerns as the provision of good public transport, power grids and sanitation are the psychological affordances of these teeming centers of human activity. With projects such as our Psychology on the Street, we are hoping to contribute to the most important discussion of all: how can urban design contribute to the mental health and resilience of a large population of overtaxed and stressed citizens? How can psychology help to make successful cities possible?
What are your research interests, Greg?
I work in the nexus of biology and psychology, studying the impacts of nature experience on human cognitive function, mood, and emotion regulation.
You've just published a research study that looks at the links between nature and mental health. What got you interested in this subject?
My interest in this area comes from a desire to investigate the value that natural landscapes may provide for people with respect to mental health. Following in the footsteps of the compelling work before me in environmental psychology, I set out to determine whether I would obtain empirical evidence for the impact of nature experience on cognitive function, mood, and emotion regulation, using the tools of psychology. I also want to explore ways of incorporating this evidence into urban design and decision making.
Briefly, can you describe what your study involved?
38 people came into the lab and filled out a questionnaire on their current levels of rumination (repetitive thought focused on negative aspects of the self). They also underwent a brain scan. They were randomly assigned to a 90-min walk in either a natural setting (a park near Stanford) or an urban setting (beside a busy street in Palo Alto). Upon completion of the walk, participants filled out the rumination questionnaire again, and underwent a second, follow-up scan. We analyzed whether there was a differential change in nature vs. urban walkers in both self-reported rumination (the questionnaire) and in a part of the brain that has been shown to be active during rumination (the subgenual prefrontal cortex).
What did your study find?
Participants who went on a 90-min walk through a natural environment reported lower levels of rumination and showed reduced neural activity in an area of the brain linked to risk for mental illness compared with those who walked through an urban environment.
How do you believe that exposure to nature achieves this impact on people's mental health?
This is an active area of exploration for us — and we hope to publish some findings on this soon.
Given that your study involved healthy participants, do you think the nature exposure is more likely to help prevent depression, or could it also be helpful for people who are already depressed?
We do not know the answer to how nature experience will impact rumination in depressed individuals, as our study focused on healthy participants.
What are the practical implications of your study's findings for urban planners, designers and developers?
More work needs to be done in this arena, but our work, along with the work of others, is helping to contribute to an overall body of evidence that nature experience provides benefits to human cognitive function and mood. This knowledge can inform the ways in which urban planners incorporate nature into cities, and provide accessible natural landscapes for urban and suburban residents. It can also provide support for conservation of open space and wilderness areas in policy design.
What's next for you in your research? (And what would you like to see other researchers address on this topic?)
We are exploring our hypothesis that emotion regulation shifts are a possible causal mechanism for the cognitive function and mood benefits that we have observed to be resultant from nature vs. urban experience. I hope that other researchers continue to explore both the characteristics of the impacts of nature experience, possible causal mechanisms, and how these impacts may or may not be moderated by individual differences.
For people who want to learn more about the links between nature, urban design, and impact on mental health, what other research studies or other resources do you recommend they might like to read?
There is more to list here than room allows, but I would start with a great textbook which was recently published entitled Environmental Psychology by Linda Steg (Editor), Agnes E. van den Berg (Editor), Judith I. M. de Groot (Editor)— it includes a great overview of theory and some of the classic studies in this area.
Learn more about Greg Bratman's study:
Read the original research paper in the Proceedings of the National Academy of Sciences of the United States of America.
Read about the research in the New York Times.
Watch Greg talk about his research in this video:
Sanity and Urbanity: