For many years, Robert Jay Lifton has been recognized as a leading “psychohistorian,” or as he prefers to define his vocation, a “historically minded psychiatrist.” Psychohistory is the field of inquiry that explores the psychological motives of individuals and groups of historical actors, as well as the psychological impact of historical events. Lifton is perhaps best known as the author of “Death in Life: Survivors of Hiroshima,” published in 1967, which received a National Book Award. In that book, he described how the hibakusha, those residents of Hiroshima who survived the atomic bomb on Aug. 6, 1945, lived with deep and shameful feelings of being “inwardly poisoned” by their experience, as well as an embittered “sense of special knowledge” that set them apart from those who had not witnessed the horrors of the attack.

“Witness to an Extreme Century” is a memoir of Lifton’s life and career, and as one is forewarned by its title, he doesn’t offer readers many laughs. Still, one passage toward the end did make me smile. “Dad,” he reports his daughter, Natasha, once asking him, “have you ever considered taking up more cheerful subjects?”

Apparently not. Lifton, whose academic affiliations include stints at the City University of New York, Yale and, most recently, Harvard, has devoted himself to studying how individuals have coped with extreme circumstances: war, torture, genocide. In addition to Hiroshima survivors, his subjects have included Vietnam veterans, the victims of Chinese Communist “thought reform,” and German concentration camp doctors.

“Witness to an Extreme Century” is a work of intellectual autobiography. Mentors, including Lifton’s fellow psychohistorian Erik Erikson, the sociologist David Riesman and the anthropologist Margaret Mead, are discussed at length, while his parents, children and wife make only occasional appearances — although there is a tribute in the epilogue to his spouse, the well-known author Betty Jean Lifton, who died in November 2010....