This document discusses cultural trauma and collective identity. It defines cultural trauma as occurring when members of a collectivity feel they have undergone a horrendous event that leaves an indelible mark and changes their future identity. Trauma is socially constructed through symbolic representation of events and narrative construction. For a trauma to shape collective identity, social actors must represent social pain as a threat to identity, responsibility must be attributed, and institutions mediate the trauma process as it revises identities over time. The document uses the Rape of Nanking as an example where this process of constructing cultural trauma did not fully occur.