What reduces prejudice in the real world? A meta-analysis of prejudice reduction field experiments

Despite advances to promote acceptance and equity in many countries, prejudice remains a significant social problem. Promoting intergroup harmony requires knowledge about what works to reduce prejudice in community settings. This meta-analysis of field experiments reveals the most effective intervention types and conditions for reducing negative attitudes towards minority groups in real-world settings. Across 69 intervention arms and 24,378 participants, results reveal that prejudice reduction interventions are effective at improving attitudes towards minority groups in real-world settings (d = 0.51, 95% CI [0.33; 0.68]). The prediction interval was -0.90 to 1.92. In this case, the prediction interval was particularly wide because of the high degree of heterogeneity detected in effect size. Subgroup analyses indicate that less commonly explored approaches, such as perceived variability, may have larger effect sizes than contact-based interventions. Still, more research is needed to confirm the effects of these less-researched approaches. Additionally, results show that interventions are more effective for school and college cohorts than for adults, and that the effects of prejudice reduction interventions endure over time.