The network dynamics of antiprejudice norms: A field experiment testing antiprejudice interventions in real groups

Individuals' attitudes toward members of ethnic and national outgroups can be shaped by peer norms within social networks. However, little is known about the interplay between such spontaneous normative influence processes within social networks and more formalized top-down norms communicated by institutions (e.g., schools). To test this impact, we conducted a longitudinal four-wave field experiment employing social network analysis among real groups. Students enrolled in Dutch and international psychology bachelor programs at a Dutch university were assigned to mentoring groups (N = 288 across 50 groups in the last wave). As institutional interventions, they watched an online diversity training video (vs. not, between mentoring groups) at the beginning of data collection (T1) and attended a diversity and inclusion session (within-participants) before T2. At each timepoint, participants reported attitudes toward outgroup members and friendships with students enrolled in the same program. We examined how peer norms (i.e., friends' intergroup attitudes) and institutional interventions shaped intergroup attitudes, finding that the video- and workshop-based interventions improved intergroup attitudes. However, network analyses showed limited influence of friends' intergroup attitudes on individuals' own attitudes as well as limited interactive effects of the institutional interventions and network dynamics in affecting intergroup attitudes.