A recent article in a psychology journal opens with a horrible scene, familiar from history: “two Nazi doctors calmly monitoring the vital signs of a Jewish prisoner soaking up to his neck in near- freezing water” (Waytz and Epley 2012, 70). This, the authors tell us, is an example of dehumanization. The doctors fail to recognize their shared humanity with the prisoner: they fail to empathize with their victim, which leads them to disregard his suffering, which in turn enables them to treat him in ways they would otherwise have deemed morally abhorrent.

The concept of dehumanization has assumed a prominent place in socialscientific thinking on genocide and mass atrocity. It has been called a “master category” in discussions of mass murder (Goldhagen 2009, 319) and “a chief premise in scholarly accounts of the Holocaust” – the “sine qua non” of such “large- scale evil” (see Vetlesen 2005, 93). Many scholars see dehumanization as a necessary precondition for genocide. Sociologists portray the diminishment of the victims’ human status as a “prerequisite to their destruction” (Alvarez 1997, 168). “Without dehumanization,” historians argue, “the murderers could not have committed their crimes” (Blatman 2011, 424). The president of Genocide Watch has declared dehumanization one of eight universal “stages of genocide” (Stanton 1998) and psychologists confirm that “no mass atrocities in the contemporary world have occurred without some form of dehumanization” (Kressel 2002, 172).

This current intellectual emphasis on dehumanization was greatly inspired by the encounter with the Nazi concentration camps. The camps’ imagery of dehumanization has become darkly iconic: the shaven heads and tattooed arms; the emaciated prisoners staggering about in the moments of liberation; the naked corpses bulldozed into mass graves. One of the British soldiers who liberated Bergen- Belsen said about the perpetrators: “The things they have committed, well, nobody would think they were human at all” (cited in Singer 2014). A psychologist arriving at the scene a few days after the end of the war in Europe reported that, “Any man visiting for the first time a concentration camp like Belsen would have difficulty in believing that human beings could suffer and fall so low in the scale that they no longer seemed to be ordinary men and women, but something subhuman” (Niremberski 1946, 65).