Professor Ming Kuo of the Landscape and Human Health Laboratory at the University of Illinois wanted to study the ‘bad side’ of urban areas to understand factors that contribute to anti-social behaviour. She had assumed green and natural parts of cities were a ‘nice to have’ rather than that they served any particular function.
However, the closer she looked, the more she realised that the Habitat Selection Theory, developed to try to explain why captive animals have higher death rates than those in the wild, might also apply to humans. We are housing humans with the same, functional view as we used to house animals: so long as they have food, clothing and shelter, they should be fine. Anything like greenery is an added nice-to-have, but not essential ingredient for a full life.
A neat, albeit depressing, opportunity to test the theory was presented in a Chicago housing project where some buildings were surrounded by greenery and some were not. As these buildings were all part of the same housing project, other variables remained constant. The questions she and her team asked were not so much about happiness or well-being but more about social cohesion. For example: Do you know the names of your neighbours? How likely are you to ask your neighbour to look after your kids? The overwhelming conclusion was that she “found social breakdown in buildings without trees and grass around them”.
There were certainly theories, in particular Attention Restoration Theory, that suggested that access to greenery and nature, even if only a view from a window, helped improve attention. If you lack nature, you suffer more from mental fatigue. Mental fatigue can mean that you find it harder to deal with social conflict as you become less calm, rational and empathetic. The correlation between the Chicago housing project lacking greenery and social breakdown was remarkable and corroborated by the more objective crime statistics from the Chicago Police Department.
Elsewhere in the US, programmes cleaning and greening vacant lots had a positive result on statistics such as gun assaults and burglaries in those areas. While the causes underlying these reductions are not yet clear, there are a number of factors brought about by being in (or observing) nature that are likely to contribute to changes in behaviour. A study of pharmacies in London, comparing the degree of greenery with prescriptions written for depression and related conditions, while controlling for socio-economic status, also saw a positive correlation of fewer anti-depressants prescribed in areas with increased greenery.
The conclusion seems to be that green spaces are not just an aesthetic part of a city, and not just the lungs that try and deal with pollution, but also provide a way of helping people cope, a calming influence that brings out the best in people.
Take a moment to be in nature, and breath it in.
Hidden Brain is a series of podcasts, presented by Shankar Vedantam, that tries to dig into the curiosities of why we choose one option over another, how emotion often trumps rationality and how we cope with an ever changing environment. It is eclectic and fascinating and I urge all to subscribe.