ResearchDiscussion

Human Lie Detector: The #1 Sign They’re Lying To You, Catch Liars Instantly! | Dr Leanne Ten Brinke

The Diary Of A CEO with Steven Bartlett1h 48m

Dr. Leanne ten Brinke discusses research on detecting deception and dark personality traits (psychopathy, narcissism, Machiavellianism, and sadism), explaining how these traits manifest behaviorally, their prevalence in the population, and evidence-based strategies for managing interactions with people who exhibit these characteristics.

Summary

Dr. Leanne ten Brinke, a forensic psychologist, shares extensive research on lie detection and dark personality traits. She explains that contrary to popular belief, eye contact is not a reliable indicator of deception; instead, liars typically provide fewer details, more ambiguous information, and show visible signs of cognitive effort. In studies where people attempt to detect lies, accuracy averages around 54%—barely better than chance—but this improves when people ask better questions and seek unanticipated responses rather than relying on behavioral cues.

The dark tetrad consists of psychopathy (characterized by superficial charm, manipulation, grandiosity, shallow emotions, lack of remorse, and rule-breaking), Machiavellianism (cynicism, manipulation through strategic planning), narcissism (entitlement, willingness to exploit others), and sadism (taking pleasure in others' pain). All four traits exist on a continuum rather than as binary categories. Psychopathy and narcissism are approximately 50% genetic and 50% environmental, with environmental factors including cold parenting, abuse, or conversely, overvaluation of children. About 1% of the population has clinical-level psychopathy, 2-5% has narcissistic personality disorder, and roughly 10% scores high on dark trait measures.

Ten Brinke distinguishes between grandiose and vulnerable narcissism: grandiose narcissists have inflatable egos that resist damage, becoming angry at failures, while vulnerable narcissists have fragile egos easily hurt by social rejection or negative feedback. She notes that despite assumptions about psychopaths being violent, violence is a risk factor but not a defining feature—many high-scoring individuals never engage in violent behavior.

On the topic of success, research contradicts the assumption that dark traits enable advancement. Her studies with Dacher Keltner found that psychopathic traits were associated with less influence in government and lower earnings for hedge fund managers. While narcissism and Machiavellianism may correlate with climbing organizational ranks initially, teams under leaders with high dark traits report more stress, higher turnover, and worse outcomes. Narcissistic leaders appear competent in first meetings but reveal themselves as hostile and ineffective over time.

Ten Brinke presents seven strategies for managing people with dark personality traits: establishing clear, explicit boundaries (which reduces selfish behavior even if rules are sometimes broken); avoiding giving them power over others; using rewards rather than punishments (as these personalities are reward-sensitive but punishment-insensitive); emphasizing common identity (which reduces anger in narcissists receiving criticism); becoming a detective to spot deception cues; and avoiding face-to-face negotiations where their charisma provides advantage. She emphasizes that change is possible but limited—early intervention with children showing callous traits through warm, responsive parenting can help, but adults with clinical-level traits rarely change without strong external motivation.

On deception and relationships, research shows people feel less connected to those lying to them, even when unaware of the deception, and that liars report greater loneliness. The most reliable verbal cues to deception are sparse details and tentative language, while nonverbal cues like Duchenne smiles combined with hostile language can indicate dark traits. She warns against common mistakes: believing nothing can be done, assuming others' inner experience mirrors your own, and expecting to change these personalities.

About this episode

Are you dealing with a master manipulator? Learn how to identify the hidden red flags of liars, psychopaths and narcissists before they cause lasting damage. Dr. Leanne ten Brinke, a renowned psychologist and director of the Truth and Trust Lab at the University of British Columbia, breaks down the science of deception and toxic behavior. Drawing from her extensive peer-reviewed research and her eye-opening book, Poisonous People, she shares practical, evidence-based strategies to help you recognize dark personality traits and protect your mental well being. In this episode, she explains: ■ The Warning Signs: How to spot the early behavioral red flags of the "Dark Tetrad" (psychopathy, narcissism, Machiavellianism, and sadism) before you get hurt. ■ The Manipulation Playbook: The exact psychological tactics toxic individuals use to control and deceive others, including what gaslighting actually means. ■ The Lie-Detector Myth: Why relying on eye contact, fidgeting, and body language is actually a terrible way to catch a liar. ■ The Two Faces of Narcissism: How to identify the different types (including why one completely crumbles at the slightest criticism), and the devastating toll of working for a psychopathic boss. ■ Defense Strategies: Proven techniques to outsmart dangerous personalities, set ironclad boundaries, and dramatically improve your life. Chapters 00:00:00 Intro 00:02:21 Why This Research Into Psychopathy Matters 00:02:58 Why Psychopathy Is Getting More Attention 00:04:05 Can You Spot a Psychopath in 5 Seconds? 00:05:30 How Facial Expressions Reveal What People Really Feel 00:08:56 Can You Predict If Someone Is Guilty? 00:09:59 Three Signs Someone Might Be Lying 00:13:46 Can Anyone Learn to Spot a Liar? 00:20:29 Why the Eye Contact Myth Gets Body Language Wrong 00:21:53 Psychopathy, Narcissism, Machiavellianism and Sadism Explained 00:34:49 The Biggest Myths About Psychopaths Debunked 00:36:28 How Common Are Dark Personality Traits? 00:38:05 Are Dark Traits Caused by Genetics or Childhood? 00:41:13 How to Increase Your Chances of Becoming a Good Parent 00:44:23 What Happens Inside a Psychopath's Brain? 00:46:06 Can Dark Personality Traits Be Cured? 00:49:30 Ads 00:51:32 Why Being Lied to Makes You Feel Distant 00:57:14 Can You Be Warm and Competent at the Same Time? 00:59:57 Why Dark Personality Traits Don't Get You Ahead 01:04:43 What a Real Job Applicant's Voice Note Revealed 01:09:06 How to Spot Red Flags in Dating Profiles and Relationships 01:17:08 Ads 01:18:17 Why Setting Boundaries Matters More Than You Think 01:19:36 7 Rules for Dealing With Dark Personalities 01:23:32 How to Spot Gaslighting and Coercive Control 01:27:55 7 Rules for Dealing With Dark Personalities Continued 01:35:03 How to Communicate With Dark Personalities 01:37:54 How to Become a Better Detective of People's Cues 01:38:25 Why You Should Avoid Face to Face Negotiations 01:42:18 Three Mistakes People Make With Dark Personalities 01:44:02 How the 10% Do the Damage and the Biggest Lie About Success 01:45:35 What Is the Greatest Lie We've All Been Told? Independent Fact Check: https://stevenbartlett.com/wp-content/uploads/2026/09/DOAC-Leanne-ten-Brinke-Independent-Research-Further-Reading-v1.pdf Follow Leanne: YouTube - https://link.thediaryofaceo.com/EkuzZ3K  Instagram - https://link.thediaryofaceo.com/2MRcXEs TikTok - https://link.thediaryofaceo.com/EL537g7 You can purchase Leanne’s book, ‘Poisonous People: Psychopathy, Narcissism, Manipulation, Sadism: How to Resist Them and Improve Your Life’, here: https://link.thediaryofaceo.com/3lYxLjb  Learn more from the online resources, here: Assess your own levels of (light and) dark traits - https://link.thediaryofaceo.com/1OsGuG0  Get support - https://link.thediaryofaceo.com/4F2i8Oj The Diary Of A CEO: ◼ Join DOAC circle here - https://doaccircle.com/ ◼ Buy The Diary Of A CEO book here - https://link.thediaryofaceo.com/BWjLTZK ◼ Shop The Diary Of A CEO collection: https://thediary.com/collections/shop ◼ Get email updates - https://bit.ly/diary-of-a-ceo-yt ◼ Follow Steven - https://g2ul0.app.link/gnGqL4IsKKb Sponsors: Fiverr - https://fiverr.com/diary and get 10% off your first order when you use code DIARY Wispr - Get 14 days of Wispr Flow for free at https://wisprflow.ai/steven

Key Insights

  • Ten Brinke found that people can detect subtle personality traits indicative of psychopathy in just five seconds of observation, though this requires multiple interactions across contexts for accuracy.
  • Research shows liars provide fewer details overall than truth-tellers, contradicting the common belief that liars elaborate extensively; this effect is strongest when people are caught off-guard rather than given time to prepare.
  • People consistently fail at lie detection despite confidence, achieving only 54% accuracy on average—barely above chance—because they rely on ineffective cues like eye contact, which has no research support.
  • Dark personality traits correlate with Duchenne smiles (genuine-looking smiles with eye activation) combined with hostile language, suggesting individuals with high psychopathic traits display mismatched emotional expressions.
  • Psychopathic traits were found to decrease influence in government and earnings as a hedge fund manager, contradicting the widespread assumption that these traits facilitate success in competitive environments.
  • Approximately 50% of serious crime is committed by the 1% of the population with clinical-level psychopathy, demonstrating outsized harm from a small population segment.
  • People with high dark traits are perceived as less warm, competent, and moral by interaction partners who are unaware they're being deceived, suggesting unconscious detection of dishonesty.
  • Treatment outcomes show that people with clinical psychopathy rarely change voluntarily; 93% of those observed past age 50 showed equally bad or worse behavior than earlier in life.
  • Warm, responsive parenting can reduce callous traits in at-risk children, while cold or abusive parenting and overvaluation both increase risk of developing dark personality traits.
  • Narcissism exists on a continuum with vulnerable and grandiose subtypes responding differently to threats: grandiose narcissists react to failure with anger, while vulnerable narcissists react to social rejection or criticism.
  • Ten Brinke's research on pleaders (people requesting help for missing loved ones) found that genuine pleaders received more sympathy and donations than deceptive ones, suggesting people possess some intuitive lie-detection ability.
  • Gaslighting operates by denying someone's subjective experience and perception of reality, making them dependent on the abuser's version and preventing them from seeking outside validation or help.

Topics

Deception detection and cues to lyingDark tetrad personality traits (psychopathy, narcissism, Machiavellianism, sadism)Distinction between grandiose and vulnerable narcissismGenetic vs. environmental origins of dark traitsFalse beliefs about psychopaths and violenceLeadership effectiveness of individuals with dark traitsStrategies for managing interactions with dark personalitiesGaslighting and emotional manipulationEarly intervention and treatment possibilitiesSocial impact and prevalence of dark traitsLoneliness and deception in relationshipsFace-to-face vs. written communication advantages

Transcript

If you're running a business, people have probably told you to use AI or get left behind. And I get that urgency. Still, AI doesn't fix a messy business. It exposes one. Because AI can only work with the information it can see. So if you ask AI something about your business, about stock or sales or customers or about your team, that information needs to be connected to the AI to be useful. That's the idea behind NetSuite by Oracle, the sponsor of this episode. NetSuite is the, the sponsor of this episode. NetSuite is the AI-powered business management suite that securely connects your financials, your inventory, your commerce, your HR, and your CRM into a single source of…

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