Lifton's research for the book began in 1953 with a series of interviews with American servicemen who had been held captive during the Korean War. In addition to interviews with 25 Americans, Lifton also interviewed 15 Chinese who had fled their homeland after having been subjected to indoctrination in Chinese universities. From these interviews, which in some cases occurred regularly for over a year, Lifton identified the tactics used by Chinese communists to cause drastic shifts in one's opinions and personality and "brainwash" American soldiers into making demonstrably false assertions. This work has become a classic text in the field and continues to serve as a fundamental guide in the debriefing of former cult members.