Exploring liars' strategies for creating deceptive reports

This 2013 study by Leins, Fisher, and Ross investigated what strategies liars spontaneously adopt when constructing deceptive reports, testing whether they fabricate accounts or draw on genuine past experiences. Across two laboratory studies (N=35 and N=22), the research found that the overwhelming majority of liars embedded their deception within real autobiographical memories rather than fabricating novel content, challenging a foundational assumption of most content-based deception detection methods.

Two laboratory analog studies in which participants described a truthful event, then constructed a lie about that event, and finally reported their content-selection strategies; discrete details in deceptive accounts were coded for experiential basis, frequency, recency, and typicality.

This research investigated whether liars actually fabricate stories or use alternative strategies when creating deceptive accounts. Using a two-study design, participants provided both truthful and deceptive reports about personal events, then described their deception strategies. Results showed that the majority of liars embedded real experiences into their deceptive accounts rather than fabricating entirely fictional stories. This finding challenges fundamental assumptions underlying content-based deception detection methods like CBCA and Reality Monitoring, which assume structural differences between truthful recall and deceptive fabrication.

These findings suggest that content-based deception detection methods may be less effective than assumed, as they rely on distinguishing fabricated from genuine accounts when most lies actually contain real experiential details.

Background & Context

The dominant assumption underlying most prior deception research has been that liars typically fabricate stories to account for their whereabouts, while truth tellers simply recall genuine autobiographical memories. Yet surprisingly little scientific attention had been paid to whether liars, when given the freedom to construct their own accounts, would actually choose outright fabrication as their primary strategy.

This gap in knowledge was significant because the most widely used content-based deception detection methods — including Criteria-Based Content Analysis (CBCA), Reality Monitoring (RM), and the Verifiability Approach (VA) — all rest on the foundational assumption that truthful and deceptive reports have structurally different origins. If liars were not actually fabricating but instead drawing on real memories, those tools' theoretical underpinnings would be seriously challenged.

Published in Legal and Criminological Psychology in 2013, this paper by Drew A. Leins, Ronald P. Fisher, and S. J. Ross represents a pivotal empirical contribution to deception science — one that forces a reconsideration of the liar-as-fabricator model and redirects attention toward what might be called the "embedded lie" as the dominant real-world deception strategy.

Research Design & Methodology

The researchers conducted two separate studies to evaluate the strategies liars use when selecting the content of their deceptive reports, granting participants the freedom to choose whatever content they desired. In both studies, participants followed a three-phase protocol: they first described a truthful story to identify a salient real-life event, then lied about that event, and finally reported their strategies for choosing the content of those lies.

Key methodological design elements included:

• Study 1: N = 35 participants
• Study 2: N = 22 participants
• Within-subject design: each participant served as their own baseline, first providing a truthful account before constructing a deceptive one
• Content analysis: discrete details reported in deceptive accounts were coded for whether they were experienced vs. fabricated, frequency of occurrence, recency, and typicality
• Self-report strategy elicitation: participants explicitly described how they chose what to include in their lies

The two-study replication design strengthened confidence in the findings, allowing the authors to test whether the patterns observed in Study 1 were robust and generalizable. The total combined sample of 57 participants provided convergent evidence across both experiments, with Study 2 yielding an even stronger effect than Study 1.

Results & Key Findings

The headline finding was striking and counterintuitive: liars overwhelmingly chose to report a previously experienced event for the time period they were to be deceptive about — 67% in Study 1 and 86% in Study 2. Rather than inventing fiction, the vast majority of deceivers reached into their own autobiographical memory banks to construct their deceptive accounts.

The majority of discrete details that participants included in their deceptive reports were actually experienced events — details that occurred relatively frequently, occurred relatively recently, and were typical or routine in nature. This pattern reveals a clear cognitive preference: liars prefer to anchor their deception in the familiar and the mundane.

Key results at a glance:

• 67% of liars in Study 1 used a real past experience as the basis of their lie
• 86% of liars in Study 2 used a real past experience — an even stronger replication
• Details chosen were predominantly experienced (not fabricated), frequent, recent, and routine
• Such "embedded lies" — largely true statements where only crucial details have been changed or omitted — are common and are particularly difficult to uncover.
• Content analysis methods that rely on detecting fabrications may be ineffective if liars choose to report previous experiences rather than outright inventions.

The convergence of findings across both studies, with the effect actually strengthening in Study 2, rules out the possibility that the Study 1 result was a fluke of the sample or design. The data compellingly argue that memory-based lying — not fabrication — is the default strategy of the spontaneous deceiver.

Discussion & Significance

These findings carry significant implications for the development of cognitive-based interventions for detecting deception, particularly because some methods that rely on content analysis may be ineffective when liars choose to report previous experiences rather than outright fabrications. The research challenges a foundational assumption embedded in tools like CBCA and Reality Monitoring, which presuppose that truthful memories are qualitatively richer in perceptual and contextual detail than fabricated lies.

As subsequent researchers have noted, the insight that "lies are built from truths" is crucial — lies often contain details based on real events or represent a blend of false and truthful information. Leins, Fisher, and Ross provided the first systematic empirical evidence of how often and in what manner this blending actually occurs when liars are left to their own devices. Due to the constraints of specific scenarios like alibi questioning, there are fewer opportunities for liars to embed their lies within truthful details — a strategy shown here to be commonly used.

The paper also has direct bearing on the Verifiability Approach to deception detection, which posits that liars avoid disclosing checkable details while truth-tellers freely offer them. Lie detection in settings such as insurance claims is particularly difficult because liars can easily incorporate deceptive statements within descriptions of otherwise truthful events — precisely the strategy documented here. The Leins et al. findings thus help explain why verifiability-based approaches face inherent challenges in unstructured, free-recall interview contexts.

Limitations & Considerations

Several methodological considerations temper the strength of the conclusions:

• Modest sample sizes: with N = 35 and N = 22, statistical power is limited, and the findings require replication in larger, more diverse samples
• Laboratory analog design: participants were recruited volunteers in a controlled setting, whose motivational stakes for lying differ substantially from those of real criminal suspects
• Self-report strategy elicitation: reliance on self-reports presents a limitation, as humans can be limited in their capacity to accurately self-report on their own behaviors — participants may not have full conscious access to the cognitive processes driving their strategy choices
• No stakes condition: the consequences of being detected as a liar in the laboratory pale against real-world investigative contexts, potentially affecting which strategies participants spontaneously selected
• Population specificity: the study was conducted in the United Kingdom, and cultural factors in lying strategy preference may limit generalizability across populations

Despite these limitations, the two-study design with converging results substantially increases confidence in the core finding. Future research using larger samples, real-stakes conditions, and behavioral (rather than self-report) measures of strategy use would further solidify these conclusions.

Practical Applications

For polygraph examiners and forensic interviewers, these findings underscore the importance of understanding that a deceptive subject's narrative may be largely grounded in genuine autobiographical memory. Embedded lies — those largely true statements where only crucial details have been changed or omitted — are common and particularly difficult to uncover; because they are based on mostly true memories, conventional detection approaches may be ineffective at identifying them. Examiners should therefore be cautious about assuming that a richly detailed, contextually coherent account is necessarily truthful.

The study's implications extend to interview technique development. The findings have significant implications for the development of cognitive-based interventions for detecting deception. Approaches such as asking unanticipated questions, imposing cognitive load, requesting reverse-order recall, or probing for verifiable details at specific times and locations may be more diagnostic than global content analysis alone — precisely because they force liars away from the comfortable strategy of recycling familiar past experiences. For consumers of polygraph services and the legal system alike, awareness of the embedded-lie phenomenon is essential for correctly interpreting both examination results and suspect narratives.