On June 18, 1961, a half-page ad appeared in a daily newspaper in New Haven, Connecticut. “We will pay you $4.00 for an hour of your time,” read its headline. Conducted at Yale University, the “scientific study of memory and learning” required 500 men. The ad’s bottom section contained a disclosure form, comprising an applicant’s personal and professional details, addressed to Professor Stanley Milgram. Hinged on a deceit—the study tested not “memory and learning” but obedience to authority—it sought to unravel the genocide’s psychology: “Could it be that [Adolf] Eichmann and his million accomplices were just following orders?” wondered Milgram. “Could we call them all accomplices?”