Myths of trauma and myths of cooperation. Diverse consequences of history for societal cohesion.

We propose that historical myths fall into two distinctive categories: Traumatic and cooperative. Traumatic myths, highlighting collective suffering, can undermine trust and foster conspiracy theories, whereas cooperative myths, emphasizing collective action, enhance group cohesion and within-group coalition building. Psychological and sociological evidence supports these divergent impacts of historical myths both in nations and social movements.