The Validity of Polygraph Testing: Scientific Analysis and Public Controversy

This 1985 peer-reviewed article by Saxe, Dougherty, and Cross, published in American Psychologist, critically examined the scientific validity of polygraph testing in response to Reagan administration and Department of Defense proposals to expand polygraph screening to large numbers of federal employees with access to classified information. The review identified serious deficiencies in both the theoretical rationale underlying polygraph use and the methodological quality of validity evidence, concluding that while reported accuracy figures appeared high, the integrity of those data could not be established — particularly for the large-scale screening contexts proposed. The paper served as a landmark contribution to both the scientific literature and to Congressional deliberations that ultimately shaped U.S. polygraph policy.

Systematic critical review of the existing polygraph validity literature, distinguishing between field and laboratory analog studies, evaluating ground truth criteria, and assessing construct and criterion validity across prior empirical reviews.

Published in American Psychologist during Congressional deliberations on expanded polygraph use, this landmark systematic review critically examined the scientific foundation of polygraph validity claims. The authors employed rigorous methodology to evaluate existing research, distinguishing between laboratory analog studies and field studies while assessing ground truth standards and construct validity. They found that prior reviews used inconsistent study selection criteria and that the evidence base suffered from significant methodological limitations. The review concluded that the validity of polygraph testing had not been scientifically established, particularly for large-scale government screening applications.

This influential review directly informed federal policymaking and highlighted the need for more rigorous scientific standards in evaluating polygraph validity, particularly for government security screening programs with potentially massive scope and consequences.

Background & Context

Published in March 1985 in the flagship journal American Psychologist, this landmark review by Leonard Saxe, Denise Dougherty, and Theodore Cross arrived at a pivotal moment in U.S. policy history. The review was conducted to aid Congressional consideration of efforts by the Department of Defense and President Reagan to expand use of polygraph tests to large numbers of government employees with access to classified information. Its appearance in one of psychology's most prestigious peer-reviewed outlets immediately elevated it above the typical technical literature of the polygraph community.

At the time, polygraph testing had been practiced for decades across law enforcement, the intelligence community, and private employment — yet the scientific foundations of the technology remained deeply contested. Polygraph tests to detect deceptiveness had been conducted for many years, although their validity had not yet been established. Against the backdrop of Cold War espionage anxieties and a push by the Reagan administration for sweeping security screening programs, the question of whether polygraphs could reliably identify deception became a matter of acute national importance.

The paper occupies a unique position in polygraph science because it functioned simultaneously as a scientific review and as direct input to legislative deliberation. As an exemplar of how psychological research evidence influences public policy, this study illustrates both the difficulties and potential of social science theory and research in shaping the direction of political decisions. Few peer-reviewed polygraph studies have had such a direct and documented connection to federal policymaking.

Research Design & Methodology

Saxe, Dougherty, and Cross employed a systematic critical review methodology, surveying the existing body of polygraph validity research and subjecting it to rigorous scientific scrutiny. Rather than conducting new primary data collection, the authors interrogated the quality of evidence that had been used — both by proponents and critics — to make claims about polygraph accuracy.

A central analytical task of the review was distinguishing between different types of validity evidence. The most important difference among the criterion studies examined had to do with whether they were conducted in actual field situations or in "analog" situations — field studies being those involving naturally occurring polygraph test situations where the researcher does not exercise experimental control, and does not systematically assign people to conditions of guilt or innocence. This distinction proved critical to evaluating the real-world applicability of reported accuracy figures.

Key design elements of the review approach included:

• Critical appraisal of study inclusion criteria across prior polygraph reviews, noting inconsistencies in which studies were selected
• Examination of ground truth standards used to establish guilt or innocence in validity studies (confessions, judicial outcomes, blind chart evaluations)
• Assessment of construct validity — whether physiological arousal measures are theoretically linked to deception per se
• Review of both laboratory analog and real-world field studies to gauge ecological validity of prior accuracy claims
• Evaluation of base rate effects relevant to large-scale government screening scenarios

For the most part, prior polygraph reviews did not explicitly state their study selection criteria, resulting in a number of different studies being included in various reviews, each presenting different problems for interpretations of validity. These included reports of single criminal investigations, studies using blind polygraph interpreters comparing chart evaluations to confession-based ground truth, and studies using legal professional judgment or judicial outcome as the criterion.

Results & Key Findings

The headline finding was unambiguous: the review identified serious problems with both the theoretical rationale and the quality of evidence supporting polygraph validity. Results suggested serious problems with both the theoretical rationale underlying use of polygraph tests and the quality of available evidence supporting their validity. Although previous evidence suggested that polygraph tests are highly accurate, the validity of these data was not clear, particularly for the uses proposed by the government.

The authors' findings clustered around several interconnected concerns:

• Theoretical deficit: No well-established physiological marker uniquely corresponds to deception; arousal responses are nonspecific
• Construct validity failure: Polygraph tests — particularly the Control Question Technique — lack construct validity; they do not assess deceptiveness but rather are situations designed to elicit and assess fear. Correct decisions may be obtained when subjects fear detection; however, because there is no way to determine the cause of a subject's fear or anxiety, validation is impossible.
• Evidentiary quality problems: Studies reporting high accuracy rates typically relied on methodologically weak ground truth criteria and inconsistent study selection
• False positive risk: Research demonstrated that individuals who are anxious or who feel threatened while taking the polygraph can produce false positives, indicating deception when the individual is being honest.
• Screening context concerns: High false positive rates become especially damaging when polygraphs are applied to large populations with low base rates of deception, as would be the case in mass government screening

The review also noted that since at least 1973, a number of polygraph researchers and psychologists had reviewed the available scientific literature to assess validity and reliability, with most such reviews focusing on criterion validity, while a growing number of investigations addressed construct validity. Saxe and colleagues found that even the most favorable prior reviews contained significant methodological vulnerabilities that undermined confidence in their reported accuracy figures.

Discussion & Significance

The 1985 Saxe, Dougherty, and Cross review is one of the most cited critical analyses of polygraph validity in the twentieth century. Its significance extended well beyond the academic sphere: it helped shape the Congressional debate that would eventually contribute to the Employee Polygraph Protection Act of 1988, which severely restricted private-sector polygraph use in the United States. The paper demonstrated that peer-reviewed psychology could meaningfully intervene in high-stakes public policy disputes.

A particularly important conceptual contribution was the authors' argument about the mismatch between laboratory-derived accuracy claims and the operational realities of large-scale government screening. When a test is applied to thousands of employees, even a small false positive rate generates a disproportionately large number of wrongly accused innocent individuals. This base rate argument — drawn from Bayesian reasoning — was articulated clearly for a non-technical Congressional audience, making the paper a model for science communication in policy contexts.

The review also dovetailed with concurrent government scrutiny. The U.S. Congress Office of Technology Assessment had released its own parallel assessment — Scientific Validity of Polygraph Testing — in 1983, reaching similarly skeptical conclusions. Results of the Saxe et al. review suggested serious problems with both the theoretical rationale underlying polygraph use and the quality of available supporting evidence, and while previous evidence suggested high accuracy, the validity of those data was not clear, particularly for the uses proposed by the government. The convergence of independent assessments reinforced the weight of the critique.

Limitations & Considerations

As with all systematic reviews, the conclusions of this paper are bounded by the quality and availability of the primary literature reviewed. The authors themselves acknowledged that the field lacked standardized criteria for study inclusion, making meta-analytic synthesis difficult. For the most part, polygraph reviews of the era did not explicitly state their study selection criteria, with the result that different studies were included across various reviews, each presenting different interpretive problems for validity.

• Publication date: The 1985 review predates decades of subsequent polygraph research, including more rigorous field studies and structured scoring systems developed in the 1990s and 2000s
• Policy framing: The review's explicit orientation toward Congressional use may have sharpened its critical focus, potentially underweighting evidence favorable to polygraph validity
• Construct vs. criterion validity: The paper's emphasis on theoretical and construct-level concerns, while scientifically important, may not fully capture the practical predictive utility observed in some high-quality field studies
• Countermeasure context: The threat of countermeasures — mental and/or physical acts that individuals can use to decrease polygraph accuracy and cause false negatives — was noted but not exhaustively reviewed, a gap that subsequent research has addressed more fully

Practical Applications

For polygraph practitioners and institutions that rely on the technology today, the enduring lesson of this paper is the necessity of matching the test application to the quality of supporting evidence. Polygraph tests to assess veracity are widely promoted for a range of applications despite substantial differences in professional and scientific opinion about the validity of such techniques. The Saxe et al. review established the intellectual standard — rigorous external peer review — against which all such claims should be evaluated.

For consumers and examinees, the paper's warnings about false positives remain directly relevant. The review's findings underscore why results should never be the sole basis for consequential decisions — whether in employment, security clearance, or criminal investigation. Polygraph evidence is most defensible when used as one tool within a broader investigative framework, with examiners trained to understand both the technique's capabilities and its well-documented limitations.