The Use of Personal Documents in Psychological Science

Allport argues that personal documents—autobiographies, diaries, letters, verbatim records, and similar self-revealing materials—constitute a valid and indispensable source of psychological knowledge, particularly for understanding the individual personality. The book is a sustained defense of the idiographic approach: the close, intimate study of a single life, with attention to "significant total processes" revealed in consecutive and complete life documents . Allport does not dismiss nomothetic (generalizing) methods, but he insists that knowledge of the individual cannot be reduced to knowledge of group averages or common traits. The book's chief original contribution, as one reviewer noted, is its analysis and defense of this idiographic procedure against the prevailing preference for statistical aggregation .

Allport defined a personal document as "any self-revealing record that intentionally or unintentionally yields information regarding the structure, dynamics, and functioning of the author's mental life" . The category is deliberately broad. It includes autobiographies, diaries, letters, verbatim records of interviews or speech, and artistic or projective productions. Allport was particularly interested in documents produced spontaneously for the author's own purposes rather than at a researcher's request, though he also discussed solicited materials such as questionnaires and collected life histories. He acknowledged that such documents vary enormously in candor, scope, and psychological value—some are deceptive or trivial—but he argued that even deceptive documents are psychologically informative because they reveal why the author wrote and why the record takes the form it does .

Reviewers recognized the book as the first systematic and analytical survey of its topic . Joseph Lander, writing in the American Journal of Orthopsychiatry, praised its meticulous treatment of validity problems and its insistence on distinguishing knowledge valuable for understanding a single individual from knowledge generalizable to larger groups . Ernest Burgess, in the Journal of Abnormal and Social Psychology, identified the defense of idiographic procedure as the book's chief original contribution, though he confessed to finding the dispute between idiographic and nomothetic methods "something sterile and perhaps futile" . A reviewer in Social Service Review summarized Allport's conclusion succinctly: the use of personal documents is a valid procedure in psychology . The main limitation noted was the book's orientation toward philosophical and methodological questions rather than practical clinical guidance.

Letters from Jenny (1965) is the practical application of the methodological principles articulated here. In the 1940s, Allport received a series of 301 letters from Jenny Gove Masterson, the mother of a former student's roommate, written over the last years of her life. He later published an analysis of these letters as a demonstration of the morphogenic method—the study of a single personality through its own self-revealing productions . The theoretical justification for treating such materials as legitimate psychological evidence, and the criteria for interpreting them responsibly, were worked out decades earlier in The Use of Personal Documents. Reading the two together shows Allport moving from methodological argument to concrete idiographic practice.

The provenance matters for understanding the book's purpose and genre. It was not a free-standing theoretical treatise but a commissioned appraisal, prepared for a committee chaired by Robert Redfield, which sought to assess the state of method in social science research . This explains the book's survey character, its extensive bibliography, and its concern with validity and generalization rather than with advocating a single technique. The committee's charge also positioned Allport to address an audience beyond psychology: Redfield noted in his introduction that the methodological questions examined in the monograph "stand large not only in psychology but in all the social sciences" . The book is thus an interdisciplinary methodological intervention, not merely a personality psychology monograph.

A common misconception is that Allport's defense of personal documents amounts to a rejection of quantitative or nomothetic science altogether. This is not the case. Allport consistently acknowledged the value of generalizing methods and framed the idiographic approach as a necessary complement, not a replacement. What he opposed was the assumption that nomothetic knowledge exhausts psychological knowledge—that understanding the average tells you everything worth knowing about the individual. Another misconception treats the book as a how-to manual for content analysis. It is primarily a work of methodological justification and epistemological argument, concerned with why personal documents should count as evidence and what standards of interpretation they require, not with step-by-step coding procedures.