Gratitude letters to nature: Effects on self-nature representations and pro-environmental behavioral intentions

Although gratitude is often defined as an emotion that motivates reciprocity and social connectedness, people can also experience gratitude to nonhuman entities such as nature. Despite expressions of gratitude to nature being common in many cultures, little research has examined its implications for sustainability. In two studies, we explored how writing letters of gratitude to nature increase pro-environmental behavior by leading people to see nature as large and by leading to more inclusion of nature in one's self-concept. Study 1 compared the effects of nature gratitude letters to gratitude letters to built environments and to a control condition, finding that nature gratitude letters led to greater inclusion of nature in self and greater perceptions of nature size. Although there was no direct effect on intentions to act pro-environmentally, nature gratitude letters had indirect effects leading to greater pro-environmental intentions via both increased nature size and nature inclusion. Study 2 replicated these findings and explored two potential moderators: biospheric value orientation and personal norms of positive reciprocity. Replicating Study 1, nature gratitude letters led to more nature inclusion and greater nature size, and they produced stronger self-transcendent emotions and more pro-environmental behavioral intentions. Further, an interaction showed that the benefits of nature gratitude letters on pro-environmental behavioral intentions was only significant among those with relatively greater endorsement of biospheric values. Implications for sustainability and emotions research are discussed.