According to a large (and growing) portfolio of research spanning fields of inquiry and conducted internationally over the past several decades, nature is good for our mental health.
Engagement with nature reduces stress, increases positive affect, and lowers blood pressure. It can improve our ability to pay attention to things and focus, to think creatively and abstractly, and can improve our capacity for delaying gratification.
Exposure to nature can raise our self-reported levels of self-esteem, can improve our memory performance, can lower our levels of aggression, and has been shown to aid in an array of "child development" activities and metrics, like a child's sociability, sense of self-worth, curiosity, and overall competency.
There's evidence we achieve better health outcomes when we exercise in nature (so-called "green exercise") compared to doing the same workout in a non-natural setting.
And there's evidence that exposure to nature can aid in the preservation and rehabilitation of our mental health.
Interestingly, even the mere suggestion of nature, or reference to it, can trigger some of these same positive effects.
Several studies have attempted to stimulate the stress-reducing effects of nature using virtual (visual and audible) simulations of natural spaces, with encouraging results.
But there's even evidence that just viewing images of natural spaces—looking at photographs of green fields with a blue, cloud-laden sky, for instance—can help patients recover after acute mental stress by altering their autonomic function (often measured by tracking heart rate variability, breathing, and blood pressure).
Research into this effect began in earnest in the 1970s and 1980s, after doctors and researchers noticed a marked difference in recovery from common surgical procedures in local hospitals that seemed to line up with which recovery rooms the patients were staying in.
Patients who were placed in recovery rooms with windows that faced natural settings recovered up to four-times as quickly as those without windows, or with windows that faced man-made settings; a stunning difference, rivaling what you might expect from targeted, medicinal or operative interventions.
Some posit this effect stems from our brains' alignment with natural shapes, colors, and rhythms. There's evidence that natural processes nudge us toward a less-focused state, which allows our attention to wander rather than being laser-guided at just one thing or task.
This "spreading out" of our attention is associated with a more neutral, relaxed cognitive and biological function: we're not hyper-alert for danger or fixated on responsibilities, tasks, the future or the past—we're just existing and passively parsing what's happening in the world around us, amongst shapes and colors and sounds that primitive parts of our brains associate with safety and calm.
It's not meditative because it's not ritualistic or guided, but it does seem to result in many of the same benefits of a meditation practice (especially when repeated regularly, overly time).
These late-20th century studies are why you'll often see images of trees and landscapes around doctor's offices, and why newer dentist offices have windows whenever feasible.
It's also why many hospitals have invested in "recovery gardens" where patients can wander and relax: it's good for the patient, and it's good for their recovery-room turnover.
There's even a sort of formula for what works best in these gardens: mature growth mixed with younger plants, and a combination of tree-lined horizons interspersed with water features and smaller, diverse plant-life.
A 7-to-3 ratio of greenery to hard surfaces seems to be ideal, in terms of working optimally for the most people and fitting within the available hospital real estate.
Researchers are in the process of expanding on this body of work by figuring out how this dynamic might be applied to other situations, most of them health- and wellness-related, but some of them fundamentally different.
A recent experiment conducted in late-2021, for instance, looked into how exposure to natural aesthetics might influence investment behavior.
Remarkably, it seems to make people more likely to invest, which could—if this experiment survives peer-review—suggest that our sense of situational optimism (and thus, feeling that it's worth making an investment) is tied to the same biological processes that inform our overall psychological state, which are in turn tied (in some cases) to how recently we were exposed to natural settings.
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