In the summer of 1954, the social psychologist Muzafer Sherif conducted a summer camp for 22 fifth graders in Oklahoma that doubled as an experiment on “the birth, life, and death of human-kind feelings” (157). In the mid-20th century, accepted wisdom on “mob violence, war, persecution, prejudice, and genocide” was individual predilection for “death and destruction, which escaped whenever they could, like steam from a cracked boiler” (159). This explanation relies on human depravity to explain societal ills. It ignores an actor’s situation, surroundings, and goals. Modern historians and psychologists believe violent groups “behave much like any other collection of people who come to see themselves as one” (161).

Sherif’s experiment tested his idea that because people’s definitions of human kinds change, “people’s list of essential traits for groups can be changed” (163) with changes in situational or systemic conditions. The traditional view was that human-kind feelings are unalterable elements of a person’s psyche. Sherif reasoned that because stereotypes do change, experiences must affect human-kind beliefs. Sherif concludes that stereotypes are neither a description of the person being stereotyped or merely in the mind of the person stereotyping: Rather, “[w]hat stereotypes really describe is the relationship between those two parties” (164).