Perpetration-Induced Traumatic Stress — The Psychological Consequences of Killing

Rachel M. MacNair is an American psychologist (PhD in social/personality psychology, City University of New York) who has worked at the intersection of clinical psychology and the peace-research tradition. The book is part of Praeger's Psychological Dimensions to War and Peace series — a peace-studies-aligned book series rather than a clinical-psychology imprint — and was published in 2002, seven years before Litz et al. (2009) gave the moral-injury construct its current clinical-research vocabulary. Praeger is a serious academic publisher (now part of ABC-CLIO) but the editorial location of the Psychological Dimensions series is closer to peace studies than to mainstream clinical psychiatry.

The argumentative move is to define perpetration-induced traumatic stress (PITS) as a distinct configuration of PTSD symptoms presenting in those whose trauma exposure came from being the active agent of harm rather than from being the victim or witness — soldiers, executioners, police, abortion providers, slaughterhouse workers — and to argue that the existing PTSD diagnostic frame, built around the victim case, captures the perpetrator case poorly. MacNair reviewed the existing clinical literature — including some early Shay material — and consolidated it under the PITS heading; the empirical core of the book is a secondary-data analysis of National Vietnam Veterans Readjustment Study data, supplemented by case material from the other perpetrator populations.

The relation to the contemporary moral-injury construct is structural and contested. PITS and moral injury overlap heavily on the perpetration case but diverge on three points. First, PITS is defined as a configuration of PTSD symptoms — it stays inside the psychiatric-diagnostic frame and argues for refinement within it, where the moral-injury literature argues that the relevant phenomenon exceeds the psychiatric frame. Second, PITS centres the act of killing specifically; moral injury is broader and includes betrayal cases (Shay), failure-to-prevent cases (Litz), and witnessing cases. Third, MacNair writes from a peace-research and abolitionist position — she is a long-standing pro-life and anti-death-penalty activist as well as a psychologist — and her research-programmatic stake is the argument that causing harm is psychologically damaging in ways that liberal moral theory has under-attended to.

The book has been substantially under-cited in the post-2009 moral-injury literature. Most of the major texts ( Litz et al., Sherman, Brock and Lettini) do not engage PITS directly, and the construct lives more vigorously in the peace-studies and bioethics literature than in the clinical moral-injury one. The reasons are partly disciplinary location (Praeger's Psychological Dimensions series did not have Clinical Psychology Review's reach) and partly research-programmatic (MacNair's pro-life and anti-death-penalty positions made the book read in some clinical circles as more political than clinical, fairly or not).

The stake is empirical-political. MacNair is arguing for a refined diagnostic category that takes perpetration seriously as its own kind of trauma, and the political implication — that participation in killing, including in state-authorised killing, is psychologically damaging in ways that should bear on policy decisions about war, capital punishment, and abortion — is on the surface of the argument. The Wiley Encyclopedia of Peace Psychology entry on PITS, written later by MacNair, is the most efficient short summary of the construct.

For the moral-injury corpus PITS is the principal adjacent diagnostic construct and the most under-engaged-with predecessor of the contemporary perpetration-side of moral injury. Reading MacNair alongside Litz et al. (2009) makes visible what was preserved (the emphasis on perpetration), what was added (the moral and spiritual content), and what was set aside (the strict psychiatric-diagnostic framing) in the consolidation of moral injury as the field's working construct.