A Novel Electroencephalography-Based Paradigm to Measure Intergroup Prosociality: An Intergenerational Study in the Aftermath of the Genocide Against Tutsis in Rwanda

Studying how intergroup prosociality evolves in war-torn societies is critical for gaining a better understanding of conflict perpetuation. Rwanda provides a unique example of how two groups must reconcile and manage their intergroup biases following a genocidal process. In this study, we employed a novel intended behavior task to measure intergroup prosociality among former genocide perpetrators, genocide survivors, and their children in Rwanda. Participants were required to choose between various individuals representing their own in-group or their out-group as recipients of their prosocial intentions. We measured how frequently they selected in-group or out-group individuals and to what extent choosing each individual induced cognitive conflict, as measured by reaction times (RTs) and midfrontal theta (FM theta) activity. The results indicated that survivors and their children selected former perpetrators and their offspring less frequently. Furthermore, selecting them involved a higher cognitive conflict, as evidenced by longer RT and a higher FM theta, compared to choosing their own in-group. For the group composed of former perpetrators and their children, we observed a dissociation. They selected out-group individuals more frequently, perhaps as a compensatory behavior for their past wrongdoings. Nonetheless, selecting the out-group individuals involved a higher cognitive conflict than selecting their own in-group. Importantly, we observed a similar intergroup prosociality bias in the children of both survivors and former perpetrators, mirroring that of their parents. These results are important for understanding how past conflicts influence intergroup prosociality bias and the extent to which this bias is transmitted to the next generation.