Social tension in the aftermath of public conflicts: an ethological analysis in humans

In social mammals, conflicts are stressful events for the individuals involved. In the postconflict context, it is possible to detect the emotional state of the former opponents through the expression of displacement activities and aggressive behaviours, which indicate an increase in social tension. In humans, stressful events also induce a physiological response that leads to increased social tension behaviours. However, the variation of such behaviours in the postconflict context has never been investigated. Therefore, by conducting a video analysis of street fights recorded by closed-circuit television cameras, we explored the variation in behaviours associated with anxiety, aggression-related anger and other behaviours possibly related to both anxiety and anger (body postures and talking with gestures) in human opponents. We compared the expression of social tension behaviours before and after the eruption of the conflict and found that displacement activities (related to anxiety), aggressive behaviours (related to anger) and talking with gestures (possibly related to anxiety/anger) increased in the postconflict context, but body postures remained unchanged. Moreover, displacement activities and aggressive patterns showed a temporal variation, decreasing within 10 min following the conflict. Finally, the occurrence of anxiety-related behaviours was more sensitive to aggression intensity than anger-related behaviours, indicating that different social tension behaviours rely on different responses that might be separable. Our study highlights the importance of the ethological approach for evaluating postconflict social tension in humans, which shows a variation in its expression as observed in nonhuman primates. Following a similar comparative approach, we encourage further studies to explore the role of social tension in altering postconflict social dynamics. • Human opponents of conflicts express social tension through behavioural indicators. • Anxiety and anger-related behaviours increase in the postconflict period. • Anxiety and anger-related behaviours decrease as the time from the conflict elapses. • Anxiety-related behaviours are more sensitive to aggression intensity.