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 15 / 20 three minutes in length and designed primarily to personalize scientists rather than deliver in-depth information, it is plausible that message duration may have constrained the depth of engagement required to foster meaningful motiva- tional shifts. Messenger Attributes Along with the message itself, we investigated if some messenger attributes—age, sex, attractiveness, presenting in natu- ral setting or not and presenting with family members or not—influence viewers’ motivation to mitigate climate change. We expected more attractive messengers to be more persuasive and did not have specific directional hypotheses about the other messenger attributes we included in the study. Four out of the five messenger attributes on viewers motivation that we explored influenced viewers’ motivation to act on climate change—age, sex, attractiveness, presenting in natural setting or not. Having family members present in the video did not influence viewers’ motivation to act on climate change. Our prediction that more attractive messengers would be more motivating held true. This adds to the existing corpus of studies that found that attractive messengers are generally more persuasive [57–62,93]. Additionally, older, male messengers and those presenting the video in a natural setting were more motivating. This aligns with findings of Carli [63] and Sugimoto et al. [64] who found some evidence for male presenters to be evaluated

more positively. However, unlike our study, Sugimoto et al. [64] did not find any evidence of age on popularity of videos and Newman et al. [65] found the opposite effect of age, where younger males were evaluated more positively than their female counterparts, but the presenters’ age did not predict their voting intentions. Our findings also contradict that of Gheorghiu et al. [66] who did not find any effect of gender, attractiveness, or age of the speaker on perceived scien- tific quality and entertainment values of TED talks. It is possible that the lack of significant effects of messenger attri- butes in the Gheorghiu et al. [66] study is also a result of practice and application of other communication guidelines in TED talks, which possibly levels the playing field (to some extent) for messenger attributes. It might be an inverse rela- tionship to our study, where messenger attributes might have had a more significant effect because the message was missing the fine-tuning from application of communication principles. Additionally, as in the MTS videos scientists are explaining the ‘personal relevance’ of climate change to them, this might have played a role in personal characteristics (as opposed to scientific facts that may be less personal) being more effective in motivating climate-change mitigation behavior. Our study also provides evidence that the background setting (imagery) of the video has an effect on persuasion. A natural setting was found to be more effective in motivating viewers to take action against climate change. This adds to

the growing body of work on climate imagery that shows that the images themselves can influence motivation to mitigate climate-change [60,67,69]. However, the positive effect of a natural setting in videos might be specific to that pertaining to climate change. Limitations and Future Research This study has several limitations that should be considered when interpreting the findings. First, although we employed a large and diverse U.S. sample and used a broad selection of videos from the More than Scientists website, caution should be exercised in generalizing these results to the wider American population or to all forms of climate change communi- cation. Additional studies using similar methodologies but incorporating different sets of climate-related messages and messengers, are needed to evaluate the robustness of our findings. In particular, we advise against overgeneralizing our finding that the most motivating messengers were older, attractive males presenting climate messages in natural settings. Even if this pattern is replicated in future studies, it is essential to prioritize inclusivity and diversity in climate communication. The choice of messenger should be guided not only by effec- tiveness but also by broader societal and ethical considerations.