Pathological Lying, Accusation, and Swindling: A Study in Forensic Psychology

This 1915 forensic psychology monograph by William and Mary Tenney Healy provided the first comprehensive scientific study of pathological lying, accusation, and swindling through detailed case studies of 27 individuals and analysis of 1,000 juvenile offenders. Published during the same era as early polygraph development, it established foundational definitions and psychological understanding of deception that informed the emerging field of lie detection.

Intensive case study methodology examining 27 detailed cases and statistical analysis of 1,000 young offenders (ages 6-22) seen in court and clinical settings, using clinical interviews, developmental history, and longitudinal observation to trace the formation and progression of pathological lying behaviors.

Background & Context

Published in 1915 and revised in 1926, William and Mary Tenney Healy's "Pathological Lying, Accusation, and Swindling: A Study in Forensic Psychology" emerged during a pivotal era in the scientific study of deception—the same period when William M. Marston invented the discontinuous systolic blood pressure test for deception detection in 1915 and John A. Larson created the first polygraph in 1921. While the Healys did not develop polygraph technology, their systematic psychological study of pathological liars provided critical foundational knowledge about the nature of deception that would inform the emerging field of lie detection.

William Healy was a British-American psychiatrist and criminologist who started the earliest American child guidance clinic and was a pioneer of psychoanalysis in the United States. This monograph represented one of the first comprehensive attempts to scientifically categorize and understand pathological lying as a distinct psychological phenomenon, separate from ordinary deception or mental illness.

Research Design & Methodology

This classic monograph contains a review of the literature to date, a series of twenty-seven case studies, and conclusions. The Healys employed intensive case study methodology, drawing from their analysis of 1,000 young repeated offenders carefully studied, including 694 males and 306 females, with ages ranging from 6 to 22 years (average about 16).

Their methodological approach included:

• Detailed clinical interviews and psychological assessments of juvenile offenders
• Longitudinal observation of lying patterns and behavioral progression
• Analysis of family history, developmental factors, and environmental influences
• Systematic documentation of case histories focusing on younger subjects to trace the formative development of pathological lying

The authors asserted that "the only method by which good understanding may be obtained of the types of personality and mentality involved in pathological lying, accusation, and swindling, as well as of the genetics of these tendencies, is by the detailed reading of typical case histories".

Results & Key Findings

The Healys established a landmark definition that remains influential: "Pathological lying is falsification entirely disproportionate to any discernible end in view, engaged in by a person who, at the time of observation, cannot definitely be declared insane, feebleminded, or epileptic. Such lying rarely, if ever, centers about a single event...it manifests itself most frequently by far over a period of years, or even a life time".

Key findings from their analysis included:

• Prevalence: Among their series of 1,000 juvenile offenders, 8 to 10 were genuine cases of pathological lying according to their definition, with 5 more engaging in pathological false accusations
• Gender differences: Excessive lying was found in 15% of males versus 26% of females; false accusations in 0.7% of males versus 5% of females
• Behavioral progression: The pathological liar gradually developed the tendency to swindle, with lying behavior naturally evolving into more concrete criminal acts
• Writing tendencies: Among 12 pathological liars studied, no less than 7 were given to writing compositions and stories, with three having definitely commenced long stories or novels—"most unusual among other offenders"

Discussion & Significance

The Healys' 1926 landmark text showed a split between those who believe possible impairment in reality testing is an important consideration and those who believe pathological lying is a willful act—a theoretical debate that continues in modern psychology. Early research by Healy and Healy (1915) showed pathological liars to be suggestible to misleading information, a finding with profound implications for both clinical assessment and forensic credibility evaluation.

This work laid critical groundwork for understanding deception as a psychological phenomenon distinct from simple dishonesty or mental illness. Published contemporaneously with the development of early lie detection instruments, the Healys' psychological characterization of pathological liars provided essential context for interpreting physiological deception responses. Their insights about personality characteristics, reality testing, and the progression from lying to swindling informed later theoretical frameworks for polygraph testing and credibility assessment.

Limitations & Considerations

The study reflects the limitations and biases of early 20th-century forensic psychology. The sample consisted exclusively of juvenile offenders and court-referred cases, limiting generalizability to non-criminal populations. The case study methodology, while rich in detail, lacked experimental controls and quantitative rigor by modern standards.

The work employed diagnostic concepts and terminology (references to "feebleminded," "Hutchinsonian teeth," epilepsy as character traits) that reflect outdated medical understanding. The assessment methods available in 1915 lacked the standardization and validation of modern psychological instruments. Cultural and historical context (early 1900s America) shaped interpretations in ways that may not translate to contemporary settings.

Practical Applications

This foundational work remains relevant for polygraph examiners and forensic practitioners in several ways. Understanding the psychological characteristics of pathological liars—including their suggestibility, reality testing impairments, and tendency toward fantasy—helps examiners recognize individuals who may produce atypical physiological responses during testing. The Healys' observation that when the pathological liar's attention was energetically drawn to his lies, he could be brought to at least a partial recognition of their falseness has implications for pre-test interview strategies.

For consumers and legal professionals, this work provides historical context for understanding how scientific approaches to deception detection emerged from broader psychological study of lying behavior. It illustrates that credibility assessment involves not just physiological measurement but deep understanding of individual psychology, developmental history, and behavioral patterns—principles that remain central to comprehensive forensic evaluation today.