Improving outgroup attitudes in schools: A meta-analytic review.

To provide information for educators, educational psychologists, school psychologists, and social psychologists, we conducted a quantitative meta-analytic test of n=50 studies dating from 1995 to 2015 that evaluated the effects of in-school interventions on attitudes toward outgroup members (defined as members of different ethnic or religious backgrounds or different age groups, persons with either physical or mental disabilities, or persons with other distinctive features). Overall, the analysis revealed a mean effect size of d+=0.36 with a 95% confidence interval that ranged from 0.17 to 0.55, indicating significant, moderate intervention effects, supporting the proposition that meaningful changes in outgroup attitudes can be obtained by applying anti-bias programs in schools. Results from our analysis did not provide evidence that teacher-led interventions produce positive outcomes, yet we found that interventions delivered by researchers promote positive attitudes toward outgroup members. Further, a closer examination demonstrated that one-on-one interventions are most effective at tackling intergroup attitudes. However, classroom-wide programs are more likely to be introduced into regular school activities because of their efficiency and the limited resources available for interventions.