David RandContributions
- Empirically demonstrates elite-cues theory extends to health behavior and vaccine uptake among politically polarized populations.
- Identifies partisan messaging backlash effects: out-party messaging on vaccine adoption not only ineffective but counterproductive.
- Provides mediation evidence that elite cue effects operate through perceived alignment with leader preferences (28–47% of effect).
- Clarifies mechanisms of partisan health-behavior gaps: vaccine hesitancy driven not only by misinformation but by low awareness of in-party elite support.
Method
Pre-registered survey experiment conducted March 17–24, 2021 with 1,480 Republican-identifying participants (337 already vaccinated). Participants randomly assigned to three conditions: (1) Republicans endorse — 2-minute video of former President Donald Trump endorsing vaccines + essay about Republican contributions to vaccine development; (2) Democrats endorse — 2-minute video of President Joseph Biden encouraging vaccination + parallel essay about Democratic role; (3) Neutral control — unrelated content about neckties.
Outcome measures: post-treatment vaccination intentions (among unvaccinated, N=1,143), willingness to encourage family/friends, vaccine attitudes, and perceived preferences of party leaders. Models controlled for demographics and pre-treatment vaccination intentions.
Results
Among unvaccinated Republicans, the Republicans endorse condition increased vaccination intentions compared to Democrats endorse (b = 0.028 [95% CI 0.006–0.041], t = 3.06, p = .002, 7.0 percentage-point increase for average respondent) and neutral control (b = 0.024 [0.006–0.042], t = 2.63, p = .009, 5.7 pp increase).
Mediation analysis: the effect of Republicans endorse on vaccination intentions was partially mediated by belief that Trump and Republican leaders would want the respondent to vaccinate (28% of effect vs. Democrats endorse, 47% vs. neutral control, both p < .001). The effect was not significantly mediated by belief that Republicans deserve credit for the vaccine program.
Backlash effects: across vaccinated and unvaccinated Republicans, the Democrats endorse condition reduced willingness to encourage others to vaccinate relative to Republicans endorse (b = −0.054 [−0.097, −0.0096], t = −2.4, p = .02, 10.4 pp decrease) and neutral control (b = −0.064 [−0.10, −0.020], t = −2.8, p = .004, 12.2 pp decrease). Democrats endorse also produced more negative vaccine attitudes than Republicans endorse or neutral condition.
No significant moderation by education, gender, or race.
Notes
Strength: pre-registered design with clear theoretical predictions. Uses real elite messaging (Trump's actual CPAC speech), making it ecologically valid while maintaining experimental control.
Weakness: field of study is COVID-19 vaccines during rollout; generalizability to other health domains or vaccine contexts uncertain. Backlash effects may be specific to the polarized moment or amplified by the salience of elite cues.
Forward work: authors note need to measure effects on actual vaccination behavior (not just intentions), test competing cues from multiple elite sources, and unbundle cues from party leaders vs. other partisans. Findings suggest publicizing existing Republican vaccine support may be more cost-effective than developing new messaging.
Implications for misinformation: partisan divides in vaccine uptake are not solely driven by false claims but by asymmetric messaging and low salience of counter-intuitive in-party elite support — remedying information availability may work where fact-checking alone fails.