Perpetration Induced Traumatic Stress (PITS) is a term coined by peace psychologist Rachel MacNair. It describes incidents of post traumatic stress disorder resulting from the trauma of having committing a violent act oneself, as contrasted with trauma caused by witnessing or being the recipient of a violent act. The fact that human beings experience psychological damage by committing violent acts is evidence that violence is at odds with healthy human behavior, and therefore it goes against our nature as human beings.
Resources:
PITS: What is it? Rachel MacNair