Transgenerational trauma is the psychological and physiological effects that the trauma experienced by people has on subsequent generations in that group. The primary modes of transmission are the uterine environment during pregnancy causing epigenetic changes in the developing embryo, and the shared family environment of the infant causing psychologicalbehavioral and social changes in the individual.


The term intergenerational transmission refers to instances whereby the traumatic effects are passed down from the directly traumatized generation [F0] to their offspring [F1], and transgenerational transmission is when the offspring [F1] then pass the effects down to descendants who have not been exposed to the initial traumatic event - at least the grandchildren [F2] of the original sufferer for males, and their great-grandchildren [F3] for females. Transgenerational trauma can be a collective experience that affects groups of people who share a cultural identity (e.g., ethnicitynationality, or religious identity). 

Collective trauma is when psychological trauma experienced by communities and identity groups is carried on as part of the group's collective memory and shared sense of identity.