Book Summary: The Key Ideas
#1: The biophilia hypothesis and Attention Restoration Theory (ART). Peaceful elements of nature can help us cognitively and psychologically, reducing stress, recharging our cognitive energy and enhancing our creativity.
#2: The growing nature science of smell, sound and sight. Research has shown that the mere smell, sound or sight of nature can change our brains and potentially improve health and educational outcomes.
#3: The immediate and gradual benefits of nature. The more time spent in nature, the greater the reported levels of wellbeing. Research reports benefits such as improved cognition and creativity, lower stress and anxiety, and lower blood pressure, among other benefits.
#4: Nature as a therapy. There is early evidence that so-called ‘ecotherapy’ may have a positive effect on reducing symptoms of mental health problems such as depression, anxiety, PTSD and ADHD.
#5: Reconciling nature with urbanisation. The science-backed benefits of nature have significant implications for how we design areas of communities in our growing urban environments.
Book Notes: The Key Ideas in Detail
Premise of the Book
- Research is increasingly showing that people are significantly happier and healthier when they spend more time outdoors in nature.
- Yet we spend the majority of our time indoors, partly because we underestimate these benefits. (For example, American and British children today spend half as much time outdoors as their parents did.)
- As a result, across the world we are increasingly suffering from ailments made worse by time indoors, such as myopia, vitamin D deficiency, obesity and loneliness.
- Florence Williams’ book sets out on a journey to explore the latest science of nature, showing how nature affects how we think and feel, and how these benefits can be reconciled with our increased urbanisation.
Key Idea #1: The biophilia hypothesis and Attention Restoration Theory (ART)
The biophilia hypothesis:
- Popularised by entomologist E. O. Wilson, biophilia is the emotional affiliation of humans to other living organisms.
- The hypothesis suggests that peaceful elements of nature can helps us cognitively and psychologically.
- This idea is supported by an increasing body of research, which has linked time in forests and nature to reduced cortisol levels, decreases in sympathetic nervous system activity, blood pressure and heart rate, as well as indications of higher immunity.
Attention Restoration Theory (ART):
- In addition, research is now turning to understanding the impacts of nature on our creativity and attention.
- The Attention Restoration Theory (ART) argues that voluntary attention is a limited resource, and when this cognitive energy flags, we begin to make mistakes.
- Being in nature reduces the array of cognitive inputs that demand our attention in urban environments, allowing us to think more clearly and restore cognitive energy.
- The most restorative nature entices our attention but doesn’t overexert it – an idea known as ‘soft fascination’.
- The idea of attention restoration is supported by research which has linked nature exposure with higher levels of creativity, as measured by tests of convergent thinking.
- Indeed, even the effect of viewing nature photos has led to indications of clearer thinking and lower anxiety on tests.
Key Idea #2: The growing nature science of smell, sound and sight
The Science of Forest Smells:
- Smells hold power over us because the nose is the direct pathway to the brain.
- The scents that some forests release have been shown to have strong medicinal properties.
- Williams uses three examples to illustrate this:
- Phytoncide: a substance emitted by plants and trees, and it’s been shown to have antibacterial, stress-reducing properties.
- Geosmin: a compound found in soil, said to have antiviral properties.
- Coniferous essential oils: help fight atopic diseases (when applied to skin), lower cortisol (when inhaled) and reduce symptoms of asthma (when inhaled).
The Science of Nature’s Noises:
- Studies have shown that, whether awake or not, exposure to plane, train and traffic noise makes our sympathetic nervous systems react, elevating heart rate, blood pressure and stress hormones.
- In one large study, several thousand students were followed in the UK, Spain and Netherlands. Those living near airports had lower reading comprehension and memory, as well as higher hyperactivity. For every 5-decibel increase in noise, reading scores dropped by 2 months.
- Noise also appears to make places look worse to us. We rate places with more noise as less scenic.
- Conversely, the sounds of nature – and in particular, birdsong – have been linked with consistent improvements in mood and alertness.
The Science of Nature’s Sights:
- Studies of hospital views have found that beds looking out into light may lead to better clinical outcomes.
- Other studies of views in offices, schools and housing projects have linked nature views with higher productivity, lower job stress, better grades and less aggression.
- Barren views, on the other hand, seem to have opposite effects.
- Technology is offering opportunities to provide ‘fractal’ visuals, e.g. through digital screens of nature. Early research has found that these digital interventions may have similar positive cognitive, psychological and physiological effects.
Key Idea #3: The immediate and gradual benefits of nature
- Research from Finland found that the biggest incremental boost in measures of emotional wellbeing and restoration came from 5 hours per month in natural settings.
- This, it seems, is the minimum to get the vitality and restoration effects of nature. The more time spent in nature, the greater the reported levels of wellbeing.
- Williams outlines an extensive range of purported benefits to time in nature, some of which are gradual impacts, and some are immediate.
Among the many mentioned, the key areas are as follows:
- Improved cognition and creativity: For example, various studies have linked walking, and specifically walking outside in nature, with improved cognition and creativity, as well as the well-documented health benefits. (The addition of technology to such walks can undermine these cognitive benefits.)
- Reduced income-related health disparities: Research has linked greener neighbourhoods with reduced income-related health disparities. In areas with the least green, poor people were twice as likely to die as their rich neighbours. (The caveat, of course, is that correlation is not necessarily causation.)
- Lower stress and anxiety: A wide range of studies have shown that multiple types nature exposure can help lower cortisol and reduce reported stress and anxiety.
- Lower blood pressure and heart rate: Studies consistently report reduced blood pressure and heart rate after nature exposure.
Key Idea #4: Nature as a therapy
- Research shows that nature works directly on our brains but also indirectly, through the benefits of social contact and exercise.
- To this end, forest bathing programmes and so-called ‘ecotherapy’ are showing significant promise as alternative treatments for mental health problems such as depression, anxiety, post-traumatic stress disorder (PTSD), and attention-deficit hyperactivity disorder (ADHD).
- There is early evidence, for example, that days away in nature in social groups may be an effective treatment for PTSD.
- Meanwhile, forest bathing programmes are being used to treat gaming addictions in South Korea. Results of research point to reduced cortisol (an indicator of reduced stress) and improved self-esteem.
Treating children with nature:
- After school, children now spend vastly more waking hours on screens than off them.
- Research suggests our capacity for empathy and self-reflection may be challenged by replacing our analog communications with digital ones, but this isn’t the only problem.
- Rates of ADHD have increased sharply across the developed world in children.
- Nature may offer some effective relief, with studies finding that activities in nature can help reduce the symptoms of ADHD.
- But the challenge is our trend towards a smaller radius of unsupervised activity. This makes it increasingly difficult for children to spend time in nature without parental supervision.
Key Idea #5: Reconciling nature with urbanisation
- We are rapidly urbanising, and this carries some significant health risks.
- Mental health problems are higher in city dwellers, and urban living is associated with higher activity in the amygdala – the fear centre of the brain.
- But despite our urbanisation, we still prefer natural settings. In studies asking participants their favourite places, over 60% describe natural areas such as lakes, beaches, parks, gardens, or forests.
- As we all benefit from being near nature, cognitively and psychologically (even if we are just looking at it, hearing it, or smelling it) we need to be smarter with how we incorporate nature into our inevitable further urbanisation.
- That means carefully considering how we landscape our key community areas, such as hospitals, schools and neighbourhoods.