Promoting Pro-environmental Beliefs and Behaviour: Choose-Your-Own Story Futuristic Climate Game

PLOS ONE | https://doi.org/10.1371/journal.pone.0317773 March 31, 2025 6 / 18 PLOS ONE Promoting Pro-environmental Beliefs and Behaviour ensure they were paying attention. In fact, this was done to ensure all participants had the same informational background, thereby keeping learning about climate change constant across treatment conditions. In Study 2, we also included a placebo condition with no infor- mation on climate change. Participants were then randomly assigned to one of two (or three in the US context) experimental conditions: placebo or treatment. Respondents who were randomly assigned to the placebo condition played a choose-your-own-adventure fantasy game that was unrelated to climate change. In the placebo game, respondents took the role of an aspiring hero and navigated a series of adventures on the fictional Solinelia Island, for instance, by battling winged beasts that attacked the hero’s village. Respondents who made it to the end of the game discovered that their adventures on Solinelia Island may have been a dream. Respondents who were assigned to the treatment condition were invited to play the climate change related choose-your-own-adventure game. We measured all respondents’ experienced emotions and our main outcome variables, after they completed their game (either the pla- cebo or treatment game). To conclude the study, respondents were debriefed about the study objectives and thanked for their participation. Samples (study 1 and study 2). Study 1 was fielded between 19/02/2021 and 13/04/2021,

among N = 1,738 UK individuals, over the age of 18. Approximately 53% of the sample identified as women, 4% as transgender or non-binary, and the remainder as men. In terms of education, 41% of respondents reported having post-secondary education, while only 1.2% had not completed secondary school. Politically, the sample included 37.7% who identified as Conservatives, 26.8% as Labour supporters, and 9.7% as Liberal Democrat supporters. The sample demonstrated significant regional diversity, for example, with 12.7% residing in London and 14.4% in the Southeast of the UK, while only 1.9% reported living in Northern Ireland (see S1 Table). Study 2 was fielded between 28/06/2022 and 19/07/2022. The Study 2 sample consisted of N = 1,290 adult Americans, with a gender distribution of 52.6% identifying as female, 46.5% as male, and 0.85% as transgender, non-binary, or another gender identity. The participants’ ages ranged from 18 to 81 years, with an average age of 46.8. Among the 1,242 respondents who answered the partisanship question, 46.2% identified as Democrats, 28.6% as Republicans, and 25.2% as either independents or affiliated with another party. Some 30.6% of participants reported having at least a bachelor’s degree. The sample also demonstrated regional diversity, with respondents representing various geographic areas (S2 Table). Measurements Dependent variables. We are interested in three sets of outcome variables (reported in Table 2). The first measures people’s beliefs about climate change. It includes four different

questions capturing public beliefs about the anthropogenic causes of climate change and its future impact at individual and generational levels. One of these question items was measured pre- and then post-treatment (see below). A second set focuses on individuals’ support for three different pro-environmental policies, all measured post-treatment. We also capture self-reported pro-environmental behavior with two questions. The first question captures individuals’ willingness to sign a climate petition, and the second their intention to discuss climate change with different others in the future. We measured the latter question also at the start of the survey, pre-treatment. The list of descriptive statistics (e.g., sample means and standard deviations) can be found in S3-S4 Tables. Mediating variable(s). We are also interested in the emotional consequences of climate game for individuals. After playing the game, participants were asked to report the intensity