IN THIS ISSUE: A research-based approach to credibility assessment that challenges some common assumptions about detecting deception in workplace investigations.
The 54% Problem We Don’t Talk About
If you’ve been relying on reading body language, watching for nervous tics, or trusting your “gut instinct” to detect lies in workplace investigations, we have sobering news: you’re barely doing better than flipping a coin.
Research underlying Timothy R. Levine’s Truth-Default Theory reflects a longstanding finding in deception-detection research: people detect deception with only about 54% accuracy on average(and professional experience alone does not appear to solve the problem). If your organization’s investigation protocols were written before this research went mainstream, it may be worth a second look. It’s time to abandon the myths and embrace what actually works.
Key Insights That Will Change Your Approach
What Doesn’t Work:
- Looking for “shifty eyes” or nervous behavior
- Relying on verbal patterns or speech hesitations
- Trusting your intuition about who “seems” honest
- Relying on traditional behavioral lie-detection cues
What Actually Works:
- Strategic Diagnostic Questioning: Asking questions designed to produce information that can distinguish truthful from deceptive accounts
- Content Analysis: Focusing on what’s said, not how it’s said
- Progressive Interview Techniques: Building from open narratives to focused probes
- Evidence Comparison: Matching statements against verifiable facts
The Game-Changing Discovery
Controlled experiments have shown that the questions investigators ask can dramatically affect deception-detection accuracy. Research on diagnostic questioning has produced accuracy rates above 70% in multiple experiments, with some studies of expert questioning producing substantially higher results. These findings come out of decades of controlled interviewing research
The secret? It’s not about detecting lies.It’s about uncovering truth through smart questioning.
5 Practical Techniques You Can Use Tomorrow
These techniques take practice to execute well under pressure (particularly the ‘circle back’ technique). If you want to run through mock interviews before your next high stakes investigation, we can help.
- Start with the Story
Begin interviews conversationally. Ask for complete narratives before diving into specifics. - Circle Back Strategically
Return to important subjects from different angles throughout the interview. The goal is not to treat minor inconsistencies as proof of deception, but to test important details and identify areas that need further inquiry. - Probe the Periphery
Ask about details that may provide additional context: “What happened right before?” “Who else might have seen this?” - Explore Their Reasoning
Ask questions that help you understand how the witness viewed the conduct and circumstances at issue. The answers may provide useful context for evaluating the account alongside the other evidence. - Reference the Unknown
Make clear that the investigation will include other sources of information: “When I interview your colleague, what will they say?” Compare the response with the evidence you later obtain rather than treating the witness’s immediate reaction as proof of deception.
The Truth-Default Advantage
Here’s the counterintuitive truth: humans naturally tend to default toward believing others, and that’s actually adaptive. Most communication is honest. The key isn’t becoming more suspicious (it’s knowing when the available information gives you reason to investigate more deeply).
Red flags that should trigger deeper inquiry:
- Clear contradictions in the narrative
- Implausible claims given the context
- A potential motive to deceive
- Important gaps that warrant additional questioning
Real-World Application: A Case Example
Instead of: “You seem nervous. Are you lying to me?”
Try: “Walk me through exactly what happened when your supervisor left the room. I know this might seem repetitive, but details matter for my report.”
The difference? The second approach elicits information you can verify, while the first just creates defensiveness.
Why This Matters for Bias Reduction
Traditional “lie detection” can invite unconscious bias. We might mistrust someone who’s naturally anxious or whose communication style differs from our own. By focusing on content over demeanor, investigators can evaluate what people say against context and evidence rather than treating how someone looks or acts while saying it as a proxy for truthfulness. Demeanor-based credibility findings are also the ones most likely to get picked apart in litigation or by the EEOC. Content-based findings hold up better under scrutiny.
Your Action Plan
This Week: In your next interview, resist treating body language as evidence of truthfulness or deception. Instead, focus on the coherence, plausibility, and verifiability of the content.
This Month: Practice diagnostic questioning with low-stakes conversations. Ask follow-up questions that probe for detail and information that can be independently checked.
This Quarter: Review your investigation protocols. Consider whether your credibility assessments rely primarily on demeanor or on communication content, context, corroboration, and other available evidence.
Remember: Expertise Isn’t About Reading People
The most effective investigators aren’t human lie detectors.They’re skilled questioners who know how to elicit information that can be tested against the evidence. Stop trying to spot liars. Start becoming an expert at uncovering facts.
Further Resources
- Book: Duped: Truth-Default Theory and the Social Science of Lying and Deception by Timothy R. Levine
- Training Focus: Evidence-based interviewing and diagnostic questioning techniques
- Skill Development: Practice narrative analysis and question formulation