Nature and Health: Perspectives and Pathways

As many scholars have noted, research and publications on the benefits of nature experience have grown substantially over recent years. Progress has been made on empirical fronts based on perspectives from psychology, epidemiology, sociology, exposure science, urban design, and other disciplines. Studies have revealed ways in which health outcomes differ by population characteristics (e.g., socioeconomic status), individual differences (e.g., states of baseline mental health), and interactions with different types of nature (e.g., street trees vs. large parks vs. deserts) (Barnes et al., 2019; Mitchell & Popham, 2008; Mitchell, Richardson, & Shortt, 2015; Olvera-Alvarez, Browning, Neophytou, & Bratman, 2021; Tester-Jones et al., 2020; Wheeler et al., 2015; Yin, Bratman, Browning, Spengler, & Olvera-Alvarez, 2022). Together, the evidence also illustrates the importance of accounting for different ways of “operationalizing nature” (e.g., Normalized Difference Vegetation Index [NDVI]), and methods of measuring exposure (e.g., subjective vs. objective), as well as the granularity in assessments of frequency and duration (Ekkel & de Vries, 2017; Shanahan et al., 2016).

These efforts have also informed progress in the development of theories that aim to account for the observed effects of nature experience. In many (but not all) cases, natural and controlled experiments have demonstrated the consistency and reproducibility of pathways that were posited to exist decades ago with attention restoration theory and stress reduction theory (Kaplan, 1995; Ulrich et al., 1991). New theories are also emerging, including but not limited to development of the perceptual fluency account (Joye, Steg, Ünal, & Pals, 2016; Menzel & Reese, 2021), conditioned restoration theory (Egner, Sütterlin, & Calogiuri, 2020), and posited mechanisms that involve emotion regulation (Bratman, Olvera-Alvarez, & Gross, 2021; Korpela et al., 2018; Richardson, 2019) or enhanced assessment of safety in natural environments (Browning and Alvarez, 2020). Research based on a multisensory approach has also revealed the importance of accounting for multiple interacting auditory, olfactory, and other pathways that lead from nature experience to particular aspects of well-being, through psychophysiological restoration and benefits for immune function (Buxton, Pearson, Allou, Fristrup, & Wittemyer, 2021; Kuo, 2015; Oh et al., 2017; Ratcliffe, Gatersleben, & Sowden, 2020; Wen, Yan, Pan, Gu, & Liu, 2019).

Further insight into these and other posited pathways will benefit from the attention of multiple disciplines. For example, with respect to “reduction of stress,” there are many ways in which additional specification of this concept can improve understanding of the effects of nature exposure and inform the evolution of theory. Stress has often been treated as a uniform experience in the nature and health literature—specifically, as a negative state that is beneficially impacted by nature contact. However, this approach misses many aspects of stress that are important to consider.

To begin, as Slavich (2020) summarizes, there are a multitude of definitions and operationalizations of stress in the literature, ranging from a conceptualization that emphasizes the match between situational demands and an individual's ability to cope or escape a stressor (Lazarus & Folkman, 1984; Maier & Seligman, 2016), to a disturbance or interference with goals or plans (Brown & Harris, 1978), to factors that influence self-concepts of social status (Gilbert & Allan, 1998). Broadly framed, one can see how the natural environment may play an important—but different—role in the reduction of stress according to each of these definitions.

With respect to “stress responses,” researchers point to the fact that not all should be considered in the same way—some of these responses may be helpful and even necessary under certain circumstances. As Sapolsky (2015) writes, the benefits and costs of stress can be thought of in terms of the spectrum of the “inverted-U.” Though beyond the scope of this article to discuss in detail, this model illustrates how beneficial stimulatory and enriching experiences are those that occur at the top of the inverted-U. As experiences move from this ideal spot on the spectrum to either side, they move further away from being beneficial.

To the right of the peak, they move from challenging to threatening—and thereby become stressful experiences that can be harmful. In contrast, those experiences to the left of the peak can be detrimental insofar as they represent an absence of opportunity for stimulation and enrichment. With this conceptualization in mind, we can imagine how nature might be relevant by providing experiences that are closer to the ideal spot of the spectrum. Natural elements may make an environment stimulating through the provision of interesting and fascinating stimuli, or they may buffer against overstimulation through the type of restorative processes most often associated with stress reduction theory.

Individual variability should also be considered. For example, what are the characteristics of each person's inverted-U given their lived experiences (Sapolsky, 2015)? Recent research demonstrates that childhood adversity can increase later-life vulnerability to stress (i.e., shifting an individual's curve to the left) (Nusslock & Miller, 2016). In contrast, nature interactions in childhood may contribute to later-life resilience (i.e., shifting an individual's curve to the right) (Kahn & Weiss, 2017; Li, Menotti, Ding, & Wells, 2021). These are just a few of the ways in which it is important to consider the specifics of helpful versus harmful experiences of challenge and stimulation. The cases in which they lead to stress are dependent upon a complex intersection of environment (including natural contexts) and the individual (including past experiences and preferences).

Aside from the need to resolve some conceptual challenges in the nature and health literature, there is also a call for the translation of our current scientific understanding into policies and decision-making to benefit population health (Bratman et al., 2019; Frumkin et al., 2017). Natural spaces are increasingly considered to be elements of critical urban infrastructure, due to the role they may play in addressing health inequities associated with social and physical aspects of the built environment (Hendricks & Van Zandt, 2021; Olvera-Alvarez, Appleton, Fuller, Belcourt, & Kubzansky, 2018).

This includes the consideration of co-benefits of green infrastructure, and their potential to reduce some—but not all—of the burden experienced by marginalized and underserved communities tied to urban heat island effect, air pollution, and other factors (Jennings, Reid, & Fuller, 2021; Kabisch, van den Bosch, & Lafortezza, 2017; Rigolon, Browning, McAnirlin, & Yoon, 2021). In this and other contexts, recent work has brought attention to stark inequities in access to existing urban greenspace, and the barriers and injustice that racism and discrimination pose for Black, Indigenous, and people of color (BIPOC) individuals in many natural spaces (Hoover & Lim, 2020; Rigolon, Browning, & Jennings, 2018; Roberts, 2022).

All of these arenas represent critical areas of progress in the field of nature and health, and there is much more important work to come. There is also a need to broaden and build this research to include a diversity of perspectives when it comes to understanding, experiencing, and relating to the natural world. Many of the studies from this field primarily use tools and methodologies that are limited in their capacity for measuring the health benefits of this broader range of interactions and relationships. For example, as Gallegos-Riofrío, Arab, Carrasco-Torrontegui, and Gould (2022) recently wrote, much of the work in nature and mental health has taken place within the context of the Western world, studying populations and using assessments of nature and well-being that are not globally representative. It is critical to ensure that as this work grows, so must the scope of the locations in which it takes place, the diversity of methods it employs, and the inclusivity of populations and perspectives it encompasses.

This Special Issue on Nature and Health contains two parts. Throughout each, as guest editors we focus on the inclusion of a wider set of voices and perspectives, although by no means is this effort complete. We hope that these collections will enrich the scientific discourse on nature and health by exploring more intimately and thoroughly the human relationships with nature that cannot be captured by the quantitative-based approaches that have dominated much of the literature thus far. These include personal accounts and examinations of dimensions of connection to nature, as well as a broadening of the spectrum of ways in which our relationship with and experience of the natural world influence our well-being.

Special Issue Part I opens with a narrative by Stanley (2022) that explores a lifetime persistence of sense of place from an immigrant's perspective. Stanley explores ways through which the “ecological self” is influenced throughout our lives by the landscapes of our childhood. Deep connection to specific place can inform an individual's lived experience in profound ways, even as they travel through space and time. Later in the issue, Falk (2022) shares an intimate journey that exemplifies the power that nature can have over our state of mind and psychological well-being.

Through personal experiences of spiritual discovery, Falk (2022) describes a process of finding refuge in nature from self-judgment and offers examples of how nature promotes self-acceptance and self-appreciation. Closing the issue, Dillon (2022) narrates a sobering introspective review of her life while backpacking through the North Cascades after a 65th birthday. It is an account that highlights again the capacity that is facilitated when we are absorbed in nature to find ourselves—both present and past.

Some innovative articles in this issue offer perspectives from Latin America. In the first of these articles, Caldero´n et al. (2022) explore “visions of nature” in their examination of how personal values, relationships, and judgments about naturalness differ among residents of Lima, Peru according to lived experiences and generational characteristics. They posit that these differences are crucial to consider if we are to have a full understanding of the nature-well-being connection, and they emphasize the importance of extending this understanding beyond urban forms of nature.

In another exploration of extra-urban natural settings, Garza-Teran et al. (2022) contribute a novel assessment of the effect of a 2-day excursion into the natural landscape of the Sonoran Desert on nature connectedness among residents of Hermosillo in northwestern Mexico. The focus on the desert natural landscape by Garza-Teran et al. (2022) also expands the current literature that mostly focuses on green and blue environments (although there are some exceptions, e.g., Yin et al. (2022)), with an example of a natural desert landscape that is specific to a unique region.

John et al. (2022) contribute to an important and emerging line of research focused on the potential for nature contact to provide relatively higher health benefits among socially disadvantaged communities (Mitchell & Popham 2008). Their study explores associations of green space with healthy aging among groups of participants characterized by different indicators of socioeconomic vulnerability in Australia. Research in this area supports the notion that social disadvantage—possibly mediated by chronic unhealthy stress—can become biologically embedded through inflammation-mediated changes to neuroimmune systems that may sensitize individuals to their environment, potentially amplifying their physiological response to both adverse and protective environmental cues (Ellis, Boyce, Belsky, Bakermans-Kranenburg, & Van Ijzendoorn, 2011; Hartman, Freeman, Bales, & Belsky, 2018; Nusslock & Miller, 2016).

With these and other health benefits that have been documented frequently, researchers from public health and implementation science are often interested in the ways in which this knowledge is translated into uptake of green interventions. One important consideration on this front is a deeper understanding of the tendencies that people have to interact with nature. Maddock et al. (2022) develop a scale to assess attitudes toward spending time in nature to help understand the factors that are driving individuals' intentions and plans related to nature contact.

And expanding further on the topic on nature connectedness discussed by Garza-Teran et al. (2022), Navarro et al. (2022) contribute a psychometric evaluation of the widely used Connectedness to Nature Scale among a sample from seven European cities, aiming to enable its application in a broader set of cultural contexts. These deeper understandings of attitudes and intentions, and others to come, may accelerate the development of interventions targeted at increasing nature-seeking behaviors for populations around the globe.

By no means are all perspectives on the human relationship to nature contained within these pages. Our aim in assembling its content was to platform the excellent work that represents at least some parts of this spectrum. We look forward to continuing with this focus on a diversity of perspectives in the upcoming Special Issue on Nature and Health Part II.