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 7 / 20 the survey remained manageable), leaving 41 videos for use in our survey. Video length ranged from 23 secs to 175 secs (Median = 64 secs); presenters were 24 males, 15 females and 2 joint (male and female) presenters; and settings comprised Nature (12 videos), Classrooms (9 videos), Offices (6 videos), Home (4 videos), Work/ lab (2 videos), Urban (3 videos), Professional—multiple scenes (4 videos), and Neutral—unable to determine setting (1 video). Measures Video content analysis. Videos were transcribed to text and analyzed using the Linguistic Inquiry and Word Count (LIWC) software developed by Pennebaker et al., [32]. The LIWC software provides computerized text analysis on many linguistic variables, including basic word count and pronoun usage (he/she/we, etc.), and higher-level psychological dimensions such as time orientation, affective processes, and authenticity. For the purposes of the present study, we used LIWC to provide details of the linguistic framing of each video with respect to: LIWC Summary Variables: The summary variables are normalized composites—standardized percentile scores, ranging from 1 to 99. 1. Analytical thinking: language reflecting formal, logical, and hierarchical thinking (as opposed to more informal narrative thinking). 2. Clout: language that suggests that the author is speaking from the perspective of high expertise and is confident (as opposed to tentative, humble, or anxious).

3. Authenticity: language suggesting an honest, personal, and disclosing style (as opposed to more guarded or distant). 4. Emotional tone: scores above 50 on this measure reflect language with a more positive, upbeat style (as opposed a negative tone suggestive of anxiety, sadness, or hostility – scores below 50. LIWC Drive or Motive Variables: These variables are percentages of total words within a text. 1. Affiliation: reference to others. 2. Achievement: reference to success and failure, achievement striving. 3. Power: reference relevant to status, dominance, social hierarchies. 4. Reward focus: reference to rewards, incentives, positive goals, approach. 5. Risk focus: reference to dangers, concerns, things to avoid. In addition to coding the videos on these LIWC dimensions, two independent coders also coded the videos on the following attributes: sex of presenter (K = 1.0); (subjective; as perceived by coders) age of presenter (K = .80); whether pre- senter was shown with family members (K = 1.0), or not; whether video was shot in nature, or not (K = .84). Disagreements were resolved through discussion and consensus. Attractiveness of presenter. Respondents were asked to rate the attractiveness of the main speaker(s) in each video across 11 dimensions, including: charming, likeable, good looking, photogenic, alluring. Response options ranged from 1 (not at all) to 5 (extremely). We initially expected two factors to emerge, one reflecting personability and the other physical

attractiveness. However, preliminary factor analysis unambiguously indicated single-factor solution; only the first factor had an eigenvalue greater than 1, with all items loaded above.70. An attractiveness score was computed by taking the mean of all items. (α = .97). Motivation to act. Respondents rated the extent to which the message made them feel motivated to “take action” and “seek out more information” about the topics in the videos (2 items, α = .92). Response options ranged from 1 (not at all) to 5 (extremely) and mean scores were used in subsequent analyses.