Emotion regulation contagion drives reduction in negative intergroup emotions.

When emotions occur in groups, they sometimes impact group behavior in undesired ways. Reducing group's emotions with emotion regulation interventions can be helpful, but may also be a challenge, because treating every person in the group is often infeasible. One solution is to treat a fraction of a group, and then hope the effect of the treatment will spread to other group members. To test the viability of this option, we designed an experiment to examine the impact of emotion regulation applied to different proportions of groups of six Israeli participants (N = 2659) who shared real-time responses to negative emotions-inducing political stimuli. Before interacting with each other, we treated different proportions of each group with an emotion regulation intervention called cognitive reappraisal, which involved teaching participants to reinterpret events to reduce negative emotions. The results showed that as the proportion of participants who received the treatment increased, there was a reduction in emotions within the non-treated participants. Furthermore, targeting above 40% of participants resulted in reliable group emotional change. Using semantic projection analysis, we validated the contagion of reappraisal language. These findings shed light on the conditions that enable collective emotion regulation.