I study decision-making in violent contexts, and I was struck by Paul Bloom’s assertion that perpetrators of violence don’t dehumanize their victims but, rather, see them as humans and intentionally choose to harm them as such (Books, November 27th). Bloom seems to assume that one’s reasons for acting violently are consistent over time, and that the physical and mental responses to harming someone are the same for one’s fiftieth violent act as for one’s first. In my research on the Holocaust and on the Rwandan genocide, I have found that the first time a human kills another human the experience is horrific: perpetrators describe reactions that include vomiting, shaking, recurrent nightmares, and profound trauma—much like the trauma of military veterans, who, arguably, are better trained than civilian perpetrators of genocide to deal with the consequences of killing. But, over time, the physical and emotional horror at participating in violence subsides. This, then, is when the moralizing rationale that draws on dehumanizing propaganda comes into play. How does one adapt to participation in violence? By calling on culturally available repertoires that frame violence as the morally right thing to do.

Letter to the New Yorker (Dec 11, 2017) from Aliza Luft, assistant professor of sociology, UCLA