How did psychology influence biographies written after World War I?

Following World War I, psychology fundamentally transformed biography by providing new tools to unlock personality and probe a subject's inner life. Influenced by the theories of Sigmund Freud and his successors, biographers moved away from 19th-century conventions of "hagiography" and monumental, fact-encumbered accounts.123

The influence of psychology manifested in several ways:

• Interpretative Methods: Some biographers explicitly employed psychological apparatus, such as analyzing behavior symbols, the Oedipus complex, or Jungian archetypes. Others used these insights more discreetly to suggest psychological interpretations of behavior without relying on overt terminology.1
• Psychobiography: Practitioners like Erik Erikson utilized ego psychology to explore how an individual’s "identity crisis" and adolescent development could influence culture.4
• Shift in Approach: Psychology encouraged biographers to examine their own involvement with their subjects, recognizing that emotional relationships can distort observation. It also contributed to the decline of formal autobiography, as the psychological exposure of the self became increasingly complex and uncomfortable to publish.12

While some early post-WWI "debunking" biographies used these methods to expose the flaws of historical figures, the field eventually matured into a more sophisticated, varied form of literature.2