Depolarization interventions produce only modest temporary effects on partisan animosity.

Evidence

This study comprehensively evaluates existing interventions through a meta-analysis of 77 treatments from 25 published studies and two largescale experiments. Our meta-analysis reveals that the average effect of treatments on animosity is modest (a 5.4-point shift on a 101-point scale), and decays within two weeks. We experimentally test whether stacking multiple treatments in one sitting or repeating them over time as “booster shots” enhances their impact. We find no evidence that multiple or repeated exposures produce substantially larger or more durable reductions in partisan animosity. This reveals the uneven utility of these interventions. They serve as valuable tools for testing the psychological mechanisms of polarization, but our findings indicate they are not, on their own, a scalable solution for reducing societal-level conflict. We conclude that achieving lasting depolarization will likely require a shift in focus, moving beyond individual-level treatments to address the elite behaviors and structural incentives that fuel partisan conflict. — Derek E. Holliday, Yphtach Lelkes, and Sean J. Westwood, Why Depolarization Is Hard, 3

Categorization

• ADDENDUM: Directly serves the reader’s counter-evidence purpose: small effects (~5.4 points) that decay within two weeks and that booster/repetition strategies fail to improve — evidence against dialogue-based intervention scaling, supporting elite/structural fixes.
• corroborated: 2 independent passages support this claim — Derek E. Holliday, Yphtach Lelkes, and Sean J. Westwood, Why Depolarization Is Hard: Evaluating…, 3
• XREF: connects to: Depolarization interventions barely raise out-party warmth and show no gains from repetition. — Derek E. Holliday, Yphtach Lelkes, and Sean J. Westwood, Why Depolarization Is Hard: Evaluating…, 59; Even ideal depolarization gains barely move downstream democratic attitudes. — Derek E. Holliday, Yphtach Lelkes, and Sean J. Westwood, Why Depolarization Is Hard: Evaluating…, 40; Depolarization interventions produce small, decaying effects that fail to scale or shift downstream attitudes — Derek E. Holliday, Yphtach Lelkes, and Sean J. Westwood, Why Depolarization Is Hard: Evaluating…, 18 (+8 more)

Broader Connections

• Depolarization interventions produce small, decaying effects that fail to scale or shift downstream attitudes #corroborates (0.95) — Derek E. Holliday, Yphtach Lelkes, and Sean J. Westwood, Why Depolarization Is Hard, 18
• Dialogue-based depolarization interventions produce small, short-lived effects that fail to scale. #corroborates (0.94) — Derek E. Holliday, Yphtach Lelkes, and Sean J. Westwood, Why Depolarization Is Hard, 8
• Depolarization interventions barely raise out-party warmth and show no gains from repetition. #corroborates (0.93) — Derek E. Holliday, Yphtach Lelkes, and Sean J. Westwood, Why Depolarization Is Hard, 59
• Modest affective depolarization gains fail to shift downstream attitudes and behaviors. #corroborates (0.90) — Derek E. Holliday, Yphtach Lelkes, and Sean J. Westwood, Why Depolarization Is Hard, 41
• Even ideal depolarization gains barely move downstream democratic attitudes. #expands (0.88) — Derek E. Holliday, Yphtach Lelkes, and Sean J. Westwood, Why Depolarization Is Hard, 40
• Depolarization interventions work in lab settings but fall short of reversing societal polarization. #corroborates (0.88) — Derek E. Holliday, Yphtach Lelkes, and Sean J. Westwood, Why Depolarization Is Hard, 73
• Stacking multiple depolarization interventions does not amplify their effect on out-party warmth. #expands (0.85) — Derek E. Holliday, Yphtach Lelkes, and Sean J. Westwood, Why Depolarization Is Hard, 61
• Deeper-engagement interventions likely reduce partisan animosity more durably. #contradicts (0.82) — Rachel Hartman et al., Interventions to Reduce Partisan…, 72
• Deliberation polarization effects decay is unmeasured since few studies track long-term effects. #qualifies (0.80) — Didier Caluwaerts et al., Deliberation and Polarization, 105
• Partisan warmth shifts only matter if they alter downstream democratic behavior. #qualifies (0.78) — Derek E. Holliday, Yphtach Lelkes, and Sean J. Westwood, Why Depolarization Is Hard, 36
• Deliberation depolarizes only when structured by deliberative-democracy design features, otherwise discussion polarizes. #qualifies (0.72) — Didier Caluwaerts et al., Deliberation and Polarization, 18