Effectiveness of Control Questions Answered ‘Yes’: Dispelling a Polygraph Myth

Experimental study challenging the widely held belief that 'yes' answers to control questions reduce polygraph test accuracy.

Controlled experiment comparing CQT accuracy when control questions are answered 'yes' versus 'no'.

Honts, Raskin, and Kircher challenged a persistent examiner belief that 'yes' answers to control questions compromise test accuracy. Their experimental data showed no significant accuracy difference between yes and no responses, dispelling this myth. The finding has practical importance because some examinees naturally answer control questions affirmatively, and examiners who insist on negative answers may unnecessarily complicate the examination process.

This myth-busting finding simplified CQT administration by removing an unnecessary constraint. Examiners can accept either yes or no answers to control questions without compromising accuracy.

Background & Context

For decades, a persistent belief circulated among polygraph examiners that control questions requiring "yes" answers would compromise test accuracy. This examiner folklore held that the Comparison Question Test (CQT) could only function properly when control questions elicited "no" responses, creating a widespread practice of reformulating questions whenever examinees answered affirmatively. The constraint reflected a fundamental misunderstanding of how comparison questions actually work in the CQT framework.

Honts, Raskin, and Kircher's 1992 study directly confronted this unexamined assumption at a time when the Utah school of polygraph research was systematically evaluating CQT procedures. The research emerged from a broader effort to separate polygraph practice from tradition-based myths and establish evidence-based standards. Prior to this study, no empirical data existed to support or refute the widespread examiner belief about yes versus no answers to control questions.

Research Design & Methodology

The researchers conducted a controlled laboratory experiment systematically comparing CQT accuracy when control questions were answered with "yes" versus "no" responses. Participants underwent mock crime scenarios following established experimental polygraph protocols, creating conditions where ground truth (guilt or innocence) was known with certainty. The study employed the Utah CQT format with standardized question sequences and scoring procedures.

The experimental design manipulated control question formulation to require either affirmative or negative answers while holding all other examination variables constant. Examiners blind to the experimental manipulation evaluated physiological recordings using numerical scoring methods. Statistical analyses compared detection accuracy, decision outcomes, and physiological response patterns across the two control question formats.

• Mock crime laboratory paradigm with confirmed guilty and innocent participants
• Counterbalanced design comparing yes-answer versus no-answer control questions
• Blind chart evaluation using standardized numerical scoring
• Analysis of multiple physiological measures (cardiovascular, electrodermal, respiratory)

Results & Key Findings

No significant difference in accuracy was found between control questions answered "yes" versus those answered "no". The data comprehensively refuted the examiner myth, demonstrating that the direction of the answer had no meaningful impact on test validity. Both question formats produced equivalent classification accuracy for guilty and innocent participants, with comparable distributions of numerical scores.

Physiological response patterns to control questions showed similar discrimination power regardless of answer direction. The critical factor remained the psychological salience of the control question content, not whether examinees responded affirmatively or negatively. Statistical analyses revealed that examiner concerns about yes answers lacked empirical foundation.

• Equivalent accuracy rates for yes-answer and no-answer control question formats
• No significant differences in numerical scores across conditions
• Similar physiological response patterns to control questions in both formats
• Consistent discrimination between guilty and innocent examinees regardless of answer direction

Discussion & Significance

This myth-busting research had immediate practical significance for polygraph practice by removing an unnecessary constraint that sometimes complicated examinations. The finding clarified that control question effectiveness depends on psychological factors—the question's emotional salience and perceived threat to the examinee's self-image—rather than the mechanical direction of the verbal response. This understanding aligned with theoretical models emphasizing cognitive and emotional processing over simple stimulus-response patterns.

The study exemplified the Utah research group's systematic approach to testing polygraph assumptions empirically. By demonstrating that a widely held examiner belief lacked scientific support, the research highlighted the importance of evidence-based practice over tradition. The finding freed examiners to accept naturally occurring yes answers without reformulating questions, potentially reducing examinee confusion and improving rapport during the pretest interview phase.

Limitations & Considerations

As a laboratory study, the research employed mock crime scenarios rather than actual criminal investigations, raising standard questions about generalizability to field conditions where stakes are substantially higher. The participant sample consisted of community volunteers who may differ psychologically from actual criminal suspects or screening examinees facing genuine consequences. However, the study's focus on a specific technical question—answer direction effects—made it well-suited to experimental control.

The findings specifically addressed probable-lie comparison questions in the CQT format and may not directly extend to other questioning techniques such as directed-lie tests or screening formats. Nevertheless, the theoretical implications about psychological salience versus answer direction likely apply broadly across CQT variants.

Practical Applications

This research simplified CQT administration by eliminating the need for examiners to insist on negative responses to all control questions. When examinees naturally answer control questions affirmatively during the pretest phase, examiners can proceed without awkward reformulation that might disrupt the psychological dynamics of the test. This flexibility particularly benefits situations where probable-lie questions genuinely apply to an examinee's history, making affirmative responses psychologically authentic.

For consumers and attorneys evaluating polygraph procedures, the study demonstrates that scientifically unsupported examiner beliefs can persist in practice until systematically tested. The research underscores the importance of evidence-based polygraph protocols over examiner folklore. Modern CQT practitioners should feel confident accepting either yes or no answers to control questions, focusing instead on psychological salience and proper question construction.