Becoming nature: effects of embodying a tree in immersive virtual reality on nature relatedness
One of the most pressing issues of the twenty-first century is to find and implement countermeasures to the ongoing climate crisis and destruction of nature. While technical solutions are being developed at a fast pace, successful implementation depends not only on the availability of technology but on creating an awareness about mechanisms of sustainable development and on transferring this awareness into actual actions on the individual level. Besides efficiency and consistency as promising technology-based strategies, a person’s relationship towards nature has been argued to be a predicting factor for sustainability-oriented behaviour within a sufficiency strategy1. Thus, it is vital for education for sustainable development that this relationship is nurtured and supported1,2. While a cognitive understanding of the impact of one’s daily actions on nature is the intellectual base for finding new solutions2, they will only be implemented if a corresponding motivation is present. The role of other species and natural systems and their importance for the ecosystem have to be understood in order for people to be able to reflect on their relatedness towards nature1,3. Thus, it requires methods that address the affective dimension, break through previous habits, and train the ability to act4,5. In the concept of Education for Sustainable Development perspective taking is argued as an approach to foster understanding and reflecting one’s relationship towards others (cognitive dimension), and by that, relating to it (affective dimension)6. Based on the idea of “perspective transformation” by Mezirow7, the experience of taking on someone else’s role, by methods as such as role-play, is discussed as a promising method to reflect on one’s own role in climate change, understand one’s personal impact on climate change and promote the ability to relate to others8. Mayer and Frantz1 argue that a feeling of connectedness to nature leads to a stronger concern for nature and can invoke action such as pro-environmental behaviour. Previous studies have shown that direct exposure to nature can strengthen a feeling of nature connectedness or nature relatedness1,9,10,11. It can also influence environmental knowledge, attitudes, or behaviour12,13,14,15. In line with environmental psychology16,17, we define nature as ‘…a broad category of natural environments and features of those environments, such as single trees or plants’ (van den Berg et al.17, p. 57). This understanding includes images of nature in the form of videos, films, or other imagery.
However, due to urbanization, it has been observed that more people live removed from nature, e.g., natural environments such as forests, and those have a low concern for nature15. Today, 82 per cent of the North American population, 81 per cent of the Latin American and the Caribbean population, and 74 per cent of the European population live in urbanized areas. This urbanization trend is predicted to grow from 55 per cent to 68 per cent of the worldwide population by 205018, with the result that the accessibility of nature, and thus the ability to experience it in person, is reduced. It then becomes harder to see oneself as part of a natural ecosystem, which in turn may lead to less concern for nature and thus less pro-environmental behaviour. At the same time, traveling to especially highly valuable ecosystems in terms of biodiversity and greenhouse gas capture as e.g., the Amazon, is neither feasible to provide a large number of humans with this kind of experience nor without risk for the local ecosystem. This raises a vital question: How can the processes of reflecting on oneself as part of the natural ecosystem be supported for those without access to natural environments, be it due to urbanization or other restrictions? The positive effects of being exposed to nature are not limited to experiences in real-world nature settings, as Meidenbauer et al.19 demonstrated. According to their study, even the act of simply looking at an image of nature or virtual environments depicting nature could achieve similar results. However, Zelenski et al.20 found that exposure to nature via video-watching can promote ‘…greater willingness to engage in environmentally sustainable behavior’ (Ref.20, p.24). These effects become more pronounced the more users perceive the experience as a real, personal one.
New solutions to provide such real, personal experiences of distant biospheres might be offered by modern immersive virtual reality (VR) technology. Thanks to highly developed technology, virtual sights of nature can be experienced with a 360°-degree angle (e.g., Nature TreksVR). Putting on a Head-Mounted-Display (HMD), users can go beyond simply looking at a landscape in front of them. Instead, users can be completely surrounded by it. Hu-Au and Lee21 argue that immersive VR technologies offer increasing engagement, provide interactive, action-oriented, affective, and empathetic experiences, and can serve as an ‘arena for visualising’ (Ref.21, p.216). Individuals can take on someone else’s perspective, close the time gap between action and consequences, get interactively involved, receive direct feedback on decisions and behaviour, see consequences, foresee future climate change scenarios, and experience sensory stimulations that can have a strong impact on affections22,23,24,25,26. The assisting role and the success of technological components in creating a convincing and captivating experience can be subsumed under the term “immersion”27, while the engagement of multiple sensory channels has been coined “sensory immersion”28. Both definitions suggest that the perceived presence is influenced by the level of immersion provided by a virtual application, and the technological components used to experience the content. This in turn influences the motivation to transfer what was learned into actions. Immersive VR technologies are defined as technologies that immerse the user as much as possible in the virtual experience, especially via the use of HMDs29, which allow the users to translate their natural head movements into camera movements within the virtual environment, providing a higher level of immersion compared to watching videos or pictures via a desktop screen30. Immersive VR shows promising potential to reduce the gap between virtual representations and real-life experiences, which are vital to fostering behavioural change. Positive effects of VR applications on motivation, knowledge, engagement, task performance, and long-term retention have already been observed in the context of learning31,32,33,34,35. Today, immersive VR technology has evolved to a point where users can enter immersive artificial environments via HMD comfortably from their own living rooms30. Worldwide, the demand for VR headsets is forecasted to reach USD 62.1 billion by 202736. Side effects such as motion sickness have become more preventable via the appropriate design of the virtual environments or by accustomization37. Devices have become affordable, do not necessarily require access to high-end PCs, and can be used with a smartphone (e.g., Google Cardboard, the Oculus Quest, Valve VR, or the HP Reverb G2). This development is a prerequisite for bringing the proverbial mountain to the prophet: It allows researchers to provide the most immersive portal to nature experiences to people who are unable to have these encounters in-person.
However, there are still only limited numbers of virtual nature applications on HMD available, and valid research results for the use of these applications in the various fields of the Sustainable Development Goals (SDGs) are still in the nascent stage26. So far, there are only few data on the cognitive, socio-emotional, or behavioural effects of immersive VR technology applied to environmental awareness. Studies on immersive nature experiences in VR have investigated effects on mood23,38, physical engagement39, green product consumption40, interest26, pro-environmental behaviour22,25,41, and nature relatedness41. In the majority of the studies, participants have been exposed to 360° videos of nature via desktop or HMD. Ahn et al.22 showed that climate-change-related applications experienced via a HMD ‘…can be strong enough to transfer into the physical world to modify behaviour’ (Ref.22, p. 85). Filter et al.26 let students experience 360° videos about the life of wolves via HMD, showing that immersive technology can foster interest in nature experiences. Klein and Hilbig25 exposed participants to nature videos of trees or birds and compared it to conditions of watching videos about social interactions or urban environments. The authors observed that watching videos of nature destruction can have a stronger impact on pro-environmental behaviour compared to experiencing a video about actual intact nature. Soliman et al.41 investigated effects of artificial nature videos vs. real nature videos on nature relatedness and pro-environmental behaviour. As one of the results, the authors observed that watching videos of nature can foster nature connectedness irrespective of the technology used (immersive VR vs. desktop screen). Mostarejan et al.38 showed that watching 360° videos of a forest via HMD has a stronger effect on mood compared to looking at pictures of a forest using HMD.
The beneficial effects of immersive VR on inter-human relationships and cognition seem to be reproducible for the interaction with the impersonal ‘other’, such as nature. Immersive VR, with its typical display mode of exploring experiences from a first-person perspective, facilitates taking on the perspective from which the experience was filmed or created. This allows the experience of embodying the portrayed agent. This is a prerequisite for the learning transfer of applications set in the context of sustainable development. Seeing the potential of what effect the mere visual experience of virtual representations of nature can have on nature relatedness, a more immersive experience such as embodiment of nature could increase the impact even further. Available VR applications can include experiences that play with what it means to see the world from another’s eyes. Experiences such as ‘The Machine To be Another’ from AnotherLab have provided insights into how swapping perspectives and embodying another person can be used to train empathy42. The beneficial effects can far surpass momentary affections: By swapping perspectives with that of female victims of domestic abuse, male offenders have not only reported increased levels of empathy towards victims but experienced the long-lasting effect of being able to better judge the emotions of others43. While the potential of embodiment, body-swapping, or body-ownership of a human in VR has been examined in various research contexts, research on non-human embodiment such as embodiment of an animal, a robot, or a plant is still in its early stages44,45,46,47. Ventre-Dominey and colleagues46 have examined the effects of embodying a robot on its acceptability. The authors observed that taking on the perspective of a robot can increase its likability as long as one´s own body movements match the movements of the robot in VR. Oyanagi and Ohmura47 focused on the effect of embodying a bird on anxiety about heights. The authors could report a decrease in self-reported fear of heights. As of now, to our knowledge, there are only two studies that focus on embodiment and its effects in the context of nature relatedness44,45. Markowitz et al.45 conducted a study comparing non-human embodiment (a coral) and human embodiment (a scuba diver) stating that ‘…the more that people reported being attuned to the virtual environment in the post-test, the more they learned in immersive VR, felt connected to nature, and reported environmental concern’ (Ref.45, p. 10). In several experiments by Ahn and colleagues44, effects on nature connectedness by being a coral and a cow were measured by comparing the VR experience via HMD to watching a desktop video. The authors observed that embodiment of a virtual other, was crucial for a high degree of connectivity to nature. They argue that embodiment in VR can foster especially the potential of perspective taking.
In our study, we transfer and expand the ongoing embodiment research to non-human and non-animal agents, and systematically compare the effects of embodying a tree between a standard viewing condition and an immersive VR (iVR) condition that displays the experience with a HMD and features the option to make small branch movements via controllers on nature relatedness. While perspective taking in itself is associated with favourable attitudes, the immersion via HMD in a virtual environment has been shown to be the determining factor of the occurrence of attitude change48. Therefore, a combination of perspective taking supported by embodiment through iVR is a promising approach to explore the transfer to a non-human, non-sentient entity in the context of climate change and nature relatedness. Thus, the aim of our study was to investigate whether experiencing the embodiment of a tree via iVR fosters a) a feeling of immersion, b) relatedness with nature, c) perspective-taking, and d) reflection on the relationship between humankind and nature. Taken this under consideration, we understand our study as continuing the conversation on how embodiment in VR technology can foster nature relatedness.
We carried out an experimental study with 28 participants in a 2 × 2 × 2 between-subjects design with condition (iVR vs. video watching) and ending (negative vs. positive) as between-subject factors and time (pre-post measurements) as a within-subject factor. Both experiencing conditions differed as follows: the iVR experience allowed for free head movement, creating the ability to look around freely. Additionally, hand-held controllers translated the users’ arm movements into a slight movement of the tree’s branches. The video desktop screen condition displayed a fixed orientation of the view and did not include the interactive element of branch movement. This decision was made based on the technical limitations of making the experience which has been developed for iVR accessible via desktop screen.
Three dependent variables (perceived immersion, nature relatedness, perspective-taking) were measured with a questionnaire that asked additional open questions to tackle further reflections on the experience of embodiment. Participants were randomly assigned to one of four conditions (iVR vs. video watching; positive vs. negative ending). As positive vs. negative endings were not of focal interest and did not yield different results, we report hypotheses and results for the factor experience condition only. Thus, the following hypotheses were tested:
H1: Experiencing the embodiment of a tree via iVR is perceived as more immersive than watching the experience as a video on a desktop screen.
H2: Experiencing the embodiment of a tree via iVR leads to higher levels of nature relatedness than watching the experience as a video on a desktop screen.
H2b: Perceived immersion levels are associated with an increase in nature relatedness.
H3: Experiencing the embodiment of a tree via iVR facilitates more perspective-taking of the tree compared to watching the experience as a video on a desktop screen.
We were also interested in exploring the subjective experience of participants concerning the reflection of their own relationship with the tree, assuming that the experience of embodiment of the tree in iVR initiates a stronger process of self-reflection than when watching a video of the same experience as a video on a desktop screen (H4). We therefore added open questions, described in measures. By the explorative combination of qualitative and quantitative data, we hope to enrich the discussion about the effects on embodiment in iVR as a tool to foster perspective-taking as one relevant goal of education for sustainable development by means of reflecting on the role of other living beings on this planet2,6,7,8.