Cracking the Code: Evidence-Based Insights into Detecting Deception

“A lie can travel halfway around the world while the truth is putting on its shoes.”

– Mark Twain

Last week we looked at empathy and fear in the interview room.  Keeping with our time in the interview room, where is our focus for detecting deception.  Are we still focusing on those non-verbal myths of our past training, or investing in what our interviewee is saying?

In the complex world of investigative interviews, detecting deception is a critical skill. From criminal investigations, to audits, to corporate inquiries, the ability to distinguish between truth and lies has profound implications. For years, non-verbal behaviors—such as fidgeting, avoiding eye contact, or changes in posture—have been considered telltale signs of deceit. However, emerging evidence-based research clearly shows that verbal and linguistic cues provide more reliable indicators of deception.

This blog explores the scientific findings on non-verbal and verbal-linguistic methods of detecting deception, shedding light on their respective merits and limitations. Are we ready to change because this is what works best or are we dogmatic in sticking to the myths of the past.

The Myth of Non-Verbal Cues in Deception Detection

Non-verbal cues have long been romanticized as a "window into the soul." Popular culture perpetuates the idea that liars can be caught through observable behaviors such as crossed arms, excessive blinking, or nervous gestures. This is what I was taught and re-taught throughout my career. However, research challenges this notion:

1. Inconsistent and Unreliable Patterns Studies show that non-verbal behaviors associated with lying often overlap with behaviors exhibited under stress or anxiety—conditions common during high-stakes interviews. For example, a suspect might avoid eye contact out of nervousness rather than deceit. Research by Vrij et al. (2008) concluded that non-verbal cues are highly context-dependent and prone to misinterpretation.
2. Over-reliance on Intuition Detecting lies through non-verbals often involves subjective interpretations. Even experienced investigators are prone to biases, leading to inaccuracies. There has been promotion of micro expressions indicating some support for observing fleeting facial expressions, but its practical application requires extensive training, it is difficult to use in an interviewing context given all we need to do, and there is no substantive research validating it efficacy.
3. Low Accuracy Rates Meta-analyses, such as those by DePaulo et al. (2003), have found that individuals—including professionals—typically achieve accuracy rates only slightly above chance when relying solely on non-verbal cues to detect deception. The whopping success rate at best is 54%.

Verbal and Linguistic Cues: A More Reliable Approach

In contrast, verbal and linguistic analyses have emerged as more effective tools for detecting deception. By focusing on what people say and how they say it, interviewers can uncover inconsistencies, cognitive load indicators, and other linguistic patterns linked to deceit.

1. Cognitive Complexity and Verbal Content Lying is cognitively demanding, as liars must fabricate information while maintaining consistency with known facts. This often results in verbal cues such as: Inconsistent Details: Liars struggle to maintain a coherent narrative over time, good questioning will reveal this. Overgeneralizations: Statements may lack specific, vivid details that truthful accounts often include. Hesitations and Pauses: Increased cognitive load can often lead to speech irregularities.
2. Language Style Matching and Pronoun Use Research has identified subtle linguistic markers of deception: Liars often use fewer self-references (e.g., "I" or "my") to distance themselves from the lie. They may overuse formal language or avoid emotional expressions to maintain control. We must listen for these inconsistencies in answers.
3. Cultural and Contextual Sensitivity Verbal analysis allows interviewers to account for cultural and situational factors, which are harder to control in non-verbal observation. Training in these methods, such as the Cognitive Interview technique, enhances accuracy and reduces biases. We all have biases, but understanding them allows us to filter that into our interpretation.

“There is nothing more deceptive than an obvious fact.”

― Arthur Conan Doyle

Combining the Best of Both Worlds

While verbal cues may hold more scientific validity, entirely disregarding non-verbal behaviors would be unwise. Non-verbals can complement verbal analysis by providing context and helping interviewers identify areas for further questioning. For instance, sudden shifts in body language might indicate discomfort when discussing a particular topic, prompting a return to that subject and deeper verbal exploration. We don’t interview with our eyes closed, watching is part of active listening.

Practical Implications for Interviews

To maximize deception detection:

1. Focus on Verbal-Linguistic Analysis: Invest in training interviewers to recognize linguistic cues and apply structured frameworks like Statement Validity Assessment (SVA) and Reality Monitoring (RM).
2. Use Non-Verbals as Supplemental Tools: Observe non-verbal behaviors as part of the overall context, not as definitive indicators.
3. Encourage Open Narratives: Allow interviewees to provide uninterrupted accounts, making it easier to analyze verbal content for inconsistencies. This is inextricably connected to asking good open-ended questions, and then listening.
4. Leverage Technology: Tools such as linguistic analysis software and transcription analysis can enhance accuracy in verbal deception detection. These however are useful post interview and don’t help us in the interview room.

Conclusion

The science of deception detection continues to evolve, challenging longstanding assumptions about non-verbal cues and emphasizing the power of verbal-linguistic analysis. While non-verbals have their place in investigative interviews, focusing on what is said—and how—offers a more reliable path to uncovering the truth. By embracing evidence-based practices, investigators can navigate the murky waters of deception with greater effectiveness, precision, and confidence.

For practitioners and investigators, aligning methodologies with research-backed approaches is key to enhancing outcomes and minimizing errors. The future of deception detection lies in science, not stereotypes and myths. It is incumbent upon interviewers to seek out training or otherwise stay abreast of developments in this scientific arena.

Anderson Investigative Associates is positioned to custom-tailor training to your specific needs.  If you have any questions or would like to discuss the issue of verbal and non-verbal deception detection, or any training need, please reach out.  Additional issues pertaining to interviewing, auditing, and investigations can be found in other blogs and videos that I have produced and are contained in most blocks of instruction that our company presents.

If you have additional questions, comments, or have an interview topic you would like me to address, give me a shout.  In the meantime, be well, stay safe out there, and get educated on best practices of deception detection to elevate your ethics and interviewing competency.  This work will improve your interviewing and communication skills in many aspects of your life. And I know who could help.

Mark A. Anderson

Director of Training and Development

Anderson Investigative Associates, llc

114 Loucks Avenue

Scottdale, PA 15683

manderson@andersoninvestigative.com

tel:912-571-6686

www.AndersonInvestigative.com

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