Affective polarization—partisan animosity rooted in group identity—has become a defining feature of American politics, with broad social and institutional consequences. Although numerous interventions aim to mitigate affective polarization, their effectiveness remains limited. Research has largely focused on identifying such interventions, yet it remains unclear whether the goal is to test theoretical mechanisms—where social science is well equipped—or to achieve societal change, which is not its role. This study presents a meta-analysis of 72 interventions from 23 studies evaluating efforts to reduce affective polarization. On average, interventions increased positive feelings toward the opposing party by five percentage points, but these effects typically dissipated within two weeks. Results from two large-scale experiments further highlight the challenge of achieving durable change. The first experiment tested whether increasing the number of treatments amplifies effects, while the second employed a panel design to assess the impact of repeated treatments spaced 10 days apart. The panel design showed that small changes could persist over time, but neither approach produced substantial or scalable reductions in polarization. There was no evidence that increased exposure or repeated dosages meaningfully enhanced effectiveness. Together, these findings suggest that current interventions yield modest, often short-lived effects and face significant barriers to scaling. If the aim is to test theory, these results provide insights into the mechanisms underlying affective polarization. However, if the goal is to reduce polarization in society, the limitations of these interventions underscore the challenges of translating social science research into lasting societal change.

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