More than scientists: How message and messenger attributes influence viewers’ climate change intentions

PLOS One | https://doi.org/10.1371/journal.pone.0331672 September 10, 2025 14 / 20 climate change because it’s a people issue” and “we have the duty to think about our actions” to left leaning audiences. Similarly, achievement-related messages, such as “it’s human nature to be problem solvers” and “food systems…... present many mitigation opportunities”, may be better targeted to right leaning audiences. Another promising approach is to craft climate change messages to target audiences across the political spectrum. For example, a video that con- tained the phrases “we know what to do’ and “we have the technology to make changes” scored high on both affiliation and achievement-related language, which offers potential to motivate both left and right leaning audiences to take climate mitigation action. Our finding that messages employing more analytic/authentic language, clout and positive emotional tone had no impact of climate change motivation in our viewers was surprising given that previous studies have found LIWC sum- mary variables to be predictive of positive viewer responses [48, 49, 52]. For example, previous studies that found that messages characterized by analytic thinking were more educational [48] and persuasive [52]; those with clout were fascinating, informative and persuasive [48]; and those with positive emotional tone and authentic styles were more popular [49]. One possible explanation for the apparent discrepancy between our weak message findings relative to previous LIWC

research is that our research focused on motivation to take climate action, whereas most previous studies assessed various dimensions of viewer positivity towards the message. It is quite possible for messages to be likeable but not motivating. The absence of a significant effect of message attributes on climate motivation may also stem from. Previous studies that looked at the influence of video messages or talks on engagement and persuasion, focused on messengers who have gained some experience or are practiced in public speaking. For example, Ozmen and Yucel [49] and Mackrill et al. [48] analyzed TED talks and found significant effects of the LIWC summary variables on viewer engagement and persuasion. TED talk speakers are generally required to follow the recommended guidelines for giving a talk, which will often include infographics and other media aids. Comparatively, most MTS videos included a frontal shot of the scientist explaining the personal relevance of climate change to them, although a few also included some visuals. Speakers are also recommended to practice their speech multiple times before they go on stage. The formal stage setting of TED talks with the presence of an audience “in-house” possibly also emphasizes the importance of communicating the ideas for the speaker, rather than simply talking about it. Studies comparing online videos and live TED talks have observed that the presence of a live audience in the latter, breaks down speaker/audience barrier [88] and improves engagement in

recorded TED talks compared to other YouTube science videos [89]. Similarly, other studies that found significant effects of the above-mentioned variables, analyzed tweets by Olympians [50] and online advertisements of pet adoptions [51]. Both message sources likely had experts in communication and public relations who created or at least edited these mes- sages. Their expertise might have added other persuasive elements to the messages that were not present in the MTS videos in our sample. Another plausible explanation for the relatively modest message effects observed in this study may relate to the sam- ple’s pre-existing engagement with climate change. Participants were, on average, more highly educated than the general population, and their willingness to watch multiple science-based videos suggests a baseline level of interest or con- cern. Moreover, participants were informed during recruitment that the study involved watching videos related to climate change, potentially attracting individuals already oriented towards the topic. Prior knowledge and existing attitudes may have attenuated the impact of message framing, as individuals who are already well-informed or active on the issue may be less susceptible to further shifts in motivation or behavioral intention [90,91]. It is also possible that the brevity of the video messages limited their motivation potential. While short-form content aligns with contemporary media consumption patterns, particularly among younger audiences, a substantial portion of

our sample was over the age of 46—a demographic that may be more accustomed to and influenced by longer, more detailed messages. Prior research suggests that longer messages can exert greater motivational impact, particularly when addressing complex issues such as climate change [92]. Given that the videos used in this study were under