Everybody needs beauty as well as bread, places to pray in and play in where nature may heal and cheer and give strength to the body and soul - John Muir
Exposure to natural environments is linked to enhanced mood and better mental health with benefits identified for both clinical and non-clinical (or community) populations. The biophilia hypothesis provided by sociobiologist Edward Wilson in 1984 suggests that humans have an innate desire to affiliate with natural environments and that humans derive positive experiences from this connection. It seems that evolution has shaped us to benefit not only physically but also psychologically from exposure to natural settings. Therefore, understanding the process through which exposure to nature exerts its influence is important. It helps to inform clinical practice as increased contact with nature potentially provides an accessible, cost-effective intervention for improving psychological wellbeing.
Psychological mechanisms at play
Nature offers an escape from daily routines and demands. Research in this area draws upon two major theories that describe how contact with nature might impact on psychological wellbeing. Attention restoration theory suggests that natural environments help us to restore our limited capacity to direct attention. According to this theory, we are only able to direct our attention for a certain amount of time before we start to feel mentally fatigued (Kaplan, 1995). Natural environments are particularly well suited for the restoration of attention. Restorativeness involves thoughts and perceptions that result in our sense of being away from the ordinary routines of life, connectedness to alternative surroundings and fascination. Certain environments are better suited to allow for the restoration of directed attention, particularly when they allow us to experience some escape from day-to-day life, immersion in something that can be explored, including stimuli that draw effortless attention, and where the setting is compatible with one’s goals. Research suggests that natural environments impact attention restoration, therefore, restorativeness might explain some of the association between nature and psychological wellbeing.
Stress reduction theory, which is closely related to the biophilia hypothesis, and sometimes referred to as a psycho-evolutionary theory, proposes that humans have evolved to respond positively to unthreatening natural environments that would have increased the chances of survival for our ancestors. It suggests that natural environments promote recovery from stress (which is distinct from attention fatigue). According to this theory, natural environments do not require extensive information to be processed, such that responses to the natural environment are immediate, unconscious and emotional. Spending time in such settings helps recovery from stress (Ulrich et al., 1991). A visual presence of natural environments may be one such stress-reducing factor as affective responses to visual stimuli deemed aesthetic may release tension. Settings that evoke interest, pleasantness and calm are usually what people have an aesthetic preference for and where recovery from stress takes place. In such settings, negative emotions tend to be replaced with positive ones, and physiological arousal tends to decrease.
“Settings that evoke interest, pleasantness and calm are usually what people have an aesthetic preference for and where recovery from stress takes place”
Natural exposure
Research has shown that access to green spaces, nature-based wellbeing interventions, or a walk in a nature setting, all led to increments in positive affect and better mental health. This has led to the use of the phrase ‘Vitamin G’ (G for green) that captures the beneficial role of natural and green environments in regular doses.
A meta-analysis of 32 studies compared the effect of exposure to natural environments and urban environments, and found that exposure to natural environments had a moderate association with higher positive affect (McMahan & Estes, 2015). Reported contact with nature in childhood has also been linked to lower symptoms of depression in adulthood, likely due to the repeated use of nature through development as an emotional regulation strategy (Snell et al., 2016). Overall, studies on the psychological benefits of exposure to nature show:
- reductions in stress levels as measured by cortisol levels and self-report
- reductions in levels of anger, stress and fatigue
- greater positive affect and lower negative affect
- reductions in symptoms of attention-deficit/hyperactivity disorder in children
- increases in happiness.
Actual versus simulated environments
Research in this field has focused on actual physical exposure to natural environments and exposure to simulated natural environments (comprising photographs, film or virtual reality). Simulated natural environments using immersive technologies that provide realistic representations of nature, such as high definition videos or interactive virtual reality, tend to result in more pronounced psychological benefits than less immersive mediums such as pictures of natural settings, with exposure to actual nature having the greatest psychological benefits.
In a recent study the impact of a virtual reality experience of a natural environment resulted in higher levels of positive affect and a greater perception of restorativeness when compared to virtual reality experience of an urban environment (Schutte, Bhullar, Stilinovic, & Richardson, 2017). In addition, restorativeness was found to be a mediating path between the virtual reality experience of a natural environment and positive affect.
Research in progress
While promoting exposure to natural environments may be an effective way of improving psychological wellbeing, for many this contact may be inconvenient or impossible as society becomes increasingly urbanised. Technological representations of nature may assist to improve indoor and urban environments where access to nature is limited such as hospitals, urban offices, apartments, and inner-city schools. Additionally, while much of the previous research has compared natural and urban environments more generally, there is limited research comparing the restorativeness or stress reducing capacity of different natural settings; it may be that not every natural environment (e.g., deserts, dense forests) will assist with positive mental health outcomes. Furthermore, exposure to traffic, noise, pollutants and visual elements that compete for our limited capacity for directed attention may contribute to the greater negative affect and higher stress outcomes often identified from contact with urban environments. Future research in collaboration with urban planners and architects, including bringing more nature into urban settings, may assist to improve the liveability of built environments.
Current state of affairs
Environmental psychology has long been promoting the benefits of nature exposure. As it happens, various environmental governance and policy frameworks (e.g., Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services) have started to recognise the role of biodiversity and ecosystems in maintaining good quality of life, over and above fulfilling the ecological production functions (e.g., supply of services). Understanding nature’s contributions to our health and wellbeing can further raise awareness among the public of the importance of natural environments and has the potential to inform nature-based clinical interventions that provide accessible, cost-effective ways to improve psychological wellbeing. Knowledge of the benefits of nature also provides an avenue for communicating the detrimental impacts of climate change on our natural environments. This can make it more personally relevant to segments of the public who are otherwise disengaged or dismissive of the anthropogenic impact on the environment.
The first author can be contacted at [email protected]