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19 important lessons from this video:

00:00:25 There are many instances where it’s important to decide whether or not a person is trying to deceive you: a policeman interviewing a suspect, a member of a jury trying to evaluate the guilt or innocence of person, a person deciding whether to become romancially involved with another person

When Neville Chamberlain first met Adolph Hitler in the late 1930s he was interested in knowing if Hitler had any ambitions of expanding his territory. After the meeting, Chamberlain incorrectly determined Hitler to be a man who could be trusted to keep his word.

00:01:37 People admit to telling 2-3 lies per day. Most of those lies are little white lies and considered to be relatively harmless and used as an act of social etiquette; to spare someone’s feelings.

On the other end of the spectrum are high-stakes lies which affect the well-being of people, and can have a major impact on society, for example murder, terrorism, and high-level politics.

[EDITOR’S NOTE: If you’re interested, check out Wikipedia’s list of 32 different types of lies.]

00:04:20 To date, the best known lie detector is the polygraph test, which measures changes in your skin conductance, heart rate, breathing level, blood pressure and finger temperature to determine whether or not you are answering a question truthfully.

  • The act of undergoing a polygraph test is stressful as the person may be afraid of being found a liar despite telling the truth. Control questions, which the interview knows to be true act as control questions to limit incorrect readings.
  • Guilty knowledge refers to things an innocent person would pay no attention to, but guilty parties would react to. For example if only the murderer knows the weapon was hidden under the bathroom sink, then only he would react to this information, while innocent people, not knowing this information, wouldn’t react.

Although polygraphs have been successful in procuring confessions out of guilty parties, those confessions must be corroborated with facts and proof. Alas, the polygraph isn’t 100% reliable, and to date is not accepted as evidence in the court of law.

00:07:51 Hypnotics and psychedelics (for example LSD or oxytocin: a drug used in intimacy, sexual reproduction and social bonding) have been tried to extract confessions, however have been found to be unreliable because these techniques only make the person more suggestible and obliging, telling the tester what they want to hear rather than the truth, and/or the drugged person’s answers will likely not make much sense.

00:09:22 Untrained lie testers have been found to be able to spot liars by reading body language with an accuracty of roughly 53% of the time, which is only slightly better than a lucky guess. Trained experts have a slightly higher %, but formal training may also actually reduce reliability because the tester feels overconfident in his or her ability to detect liars. Experienced liars have been found to be excellent lie detectors; a form of “it takes one to know one.”

[EDITOR’S NOTE: Recall in the mini-documentary Sex & Love: Interpreting Body Language & Non-Verbal Flirting Cues that everybody has that 6th sense, but some humans are masters of it while others have no idea it exists. You’d be amazed at what you can understand about other people by simply observing their actions.]

00:10:39 It takes more skill to lie than it does to detect liars. Effective liars:

  • Score high in Machiavellianism
  • Are able to monitor and control their verbal and non-verbal reactions
  • Tend to make good actors and actresses
  • Perhaps lack emotions such as guilt or anxiety which would give them away
  • May to some extent ‘believe’ their own lie
  • May employ a sort of self-hypnosis to render themselves comfortable with the lie, similar to the method acting approach where the actor connects with a character by drawing on personal emotions and memories to blend their emotions with the character to be played.

[EDITOR’S NOTE: Recall in Professor Wilson’s lecture Criminal Profiling: 14 Theories of Causes & Deterrance of Criminality for Gresham College that psychopaths are more likely to charm their way out of prison by smiling at the parole board. Research has shown that psychopaths are twice as likely to get early release from prison than non-psychopathic inmates, despite being more dangerous after release.]

00:13:00 The contours of your face can cause people to more readily-label you a liar. “Soft, feminine features such as a smooth, warm complexion, large mouth and rounded jawline (baby-faced) are judged to be more trustworthy,” whereas “macho traits such as bushy, knitted brows, facial stubble, a wide nose and small mouth” are judged to be less trustworthy.

Social psychology research shows that these stereotypes have been found to unfairly affect jury decisions and court sentences.

[EDITOR’S NOTE: Recall in the lecture How To Start A Startup: Introducing Yourself So Investors Want to Invest that Professor Frank Bernieri of the Univeristy of Toledo found that in a job interview, the interviewer makes a snap judgment about potential job candidates within the first 15 seconds of a job interview, and that initial impression of you changes very little by the end of the interview. Those 15 seconds – your first impression – acted as an anchor and determined how the interviewer perceived you: your competence, level of intelligence, trustworthiness, etc. The remainder of your meeting acts to either confirm or deny the interviewer’s first impression of you.

Further, Dr. Alexander Todorov of Princeton University took Professor Bernieri’s first impression findings even further, finding that just 100 milli-seconds was enough to predict election votes by a margin of 68-72% accuracy. Meaning that simply ‘looking’ competent may be convincing enough to get the job done.]

00:15:16 Non-verbal gestures involving arms and hands are used by the speaker to reinforce what is being said. These gestures tend to suggest an emotional involvement on the part of the speaker, which is interpreted as sincerity. However, gestures which don’t match what is being said, or speakers who use a ‘less than average’ number of gestures suggest the person is over-controlling themself and are interpreted as deceptive.

Most of this research has been conducted on students and people in normal, safe situations where they are asked to tell a true story and a fake story. This research has not been compared to high-stakes, life-threatening situations where a person must lie to avoid severe consequences.

00:17:49 Microexpressions are “brief, involuntary facial expression shown on the face of humans according to emotions experienced. They usually occur in high-stakes situations, where people have something to lose or gain. Microexpressions occur when a person is consciously trying to conceal all signs of how they are feeling, or when a person does not consciously know how they are feeling.”  In poker these microexpressions are referred to as ‘tells.’

The Facial Action Coding System (FACS) developed by Paul Ekman and made mainstream by the television series Lie to Me attempts to show the relation between muscle group movements in the face with the sincere emotion expressions to determine their level of authenticity (i.e. genuine smile versus a fake smile). This technique has been criticized because it lacks empirical validation, namely that all research has been conducted on known to be liars, while no thorough research has yet to look at the false-positives – the brief, involuntary facial expressions shon on the face of humans that in reality mean absolutely nothing whatsoever.

00:20:18 Emotional leakage is when a person’s genuine feelings & emotions are betrayed through facial expressions of the person attempting to conceal those genuine emotions.

00:26:19 It’s commonly believed that liars avoid direct eye contact with you, however this eye contact belief can be over-ridden and the liar consciously looks you in the face as they lie to you. Also, many liars may look you in the face to judge whether or not you believe them, and then adapt their lie accordingly.

[EDITOR’S NOTE: Recall in Ray Hyman’s lectures How To Convince People You Know Them Very, Very Intimately and Linguistic Tricks Con-Artists Use to Manipulate You that coldreaders use the entirety of your non-verbal cues as they tell you about your past, present and future.

Recall also in the mini-documentary Sex & Love: Interpreting Body Language & Non-Verbal Flirting Cues that men unconsciously read a woman’s body language to determine whether or not the woman has granted him permission to approach and talk to her.]

The pseudo-science Neuro-Linguistic Programming (NLP) is a behavior-modification methodology to help people overcome problems and reach goals in life, and holds that there is a difference between recalling memories and fabricating stories, and that by looking at the person’s eyes movements, you can determine whether a person is remembering a true fact or lying.


(photo from here.)

Research on this has not been proven, and all empirical efforts to prove this have failed.

Computerised eye tracking uses technology to compare a person’s eye movements while they are searching for an answer to a question with their neutral base eye movements. This method claims an 82% accuracy in detection.

00:28:51 Stress signs such as blinking, blushing, sweating, touching your face and a dry mouth aren’t very reliable indicators of lying because these signals manifest themselves on many other occasions, for example in people who are about to stand in front of an audience and give a speech or the mere fact that you are being questionned by the police.

Sometimes, the absence of stress cues can serve as a strong indication that the person is overly-controlling themselves, which suggests lying.

A person who sucks their lips into their mouth usually means that the person is uncertain and contemplating something. A person who compresses their lips is usually associated with lying, attempting to refrain from blurting out the truth; it may also indicate that the person is attempting to refrain him or herself from saying something s/he shouldn’t, such as showing your true feelings about something or being reluctant to provide sensitive information to someone.

00:33:43 A voice stress analysis involves monitoring micro-tremors in the voice and a higher-than-usual pitch to detect lying. Although efficient at detecting stress and potentially coaxing confessions out of guilty parties, empirical research hasn’t been able to prove voice stress analysis to be a reliable source of lie detection, as the stress may be due to many other factors than lying.

00:35:22 Thermal imaging through infrared cameras, already used in airports to prevent passengers found to be carrying a contageous strand of disease from travelling) correctly identified liars (69% of the time) and truth tellers (64% of the time), however standard face-to-face interviews showed much greater accuracy, being able to correctly identify liars (72% of the time) and truth tellers (77% of the time). So although thermal imaging may not yet be a reliable method of lie detection, it can act as an effective automated way of identifying in large crowds, such as in at airport customs, which passengers should receive a second, more strenuous questioning.

00:38:11 We know that lies originate in the brain, specifically in the frontal and perhaps parietal lobes because lies require suppression of the truth as well as the invention of a new, plausable scenario, whereas telling the truth only requires recalling memories.


(photo taken from Wikipedia]

Claims as high as 90% accuracy have been found using this approach, however it is possible to cheat on this test with the same cheating technique used to beat a polygraph test: manipulate the accuracy of the neutral, baseline test questions by stimulating yourself, for example by thinking of something horrible – such as shooting your girlfriend through a bathroom door.

Most courtrooms do not accept any of the above lie detection procedures as a valid form of evidence… except for some cases in India.

00:42:31 Another common belief is that a person’s speech patterns will change when they are lying, such as increased repetition and emphasis made on certain points and excessive hesitations using ‘ummm’ and ‘errrrr.’

Liars tend to show longer pauses between questions and answers, perhaps to fabricate their lie, unless the liar has already rehearsed his or her answers in advance, in which case the gap between question and answer would diminish. Likewise, the speed at which the liar is talking may slow down, thus allowing the person more time to construct their lie. Lastly, the liar may speak less and provide fewer facts and details about the story, thus lowering the chances of being proven wrong when the information is cross-checked for accuracy. Globally, liars tend to come across as negative and uncooperative.

00:43:30 The choice of words used in the answers may be a greater indicator of culpability than the non-verbal methods discussed above.

Guilty parties tend to use:

  • Indirect denials of lying such as “I’m trying to tell you the truth” as well
  • Indefinite words such as “maybe,” “perhaps,” and “I guess.” to avoid committing themselves to their lie.
  • Expanded contractions (”I did not”) rather than contractions (”I didn’t”)
  • Distancing expressions (”that woman” versus “Monica Lewinsky”)
  • Past tense (”My wife was amazing”) when the present tense would be correct (”My wife is amazing”) when talking a person who is believed missing but still alive.

00:46:30 Certain words appear more or less often in a liar’s testmony. Automated linguistic word counting analyses have proven to yield a 67% accuracy of guilt against 52% of human judges, and have noted that liars often:

  • Avoid ownership of the lie by refering to themselves as little as possible; avoid saying “I” and “me.”
  • Express more negative emotions such as hate, being sad or feeling worthless implies self-loathing
  • Use fewer words such as “except,” “but,” and “nor” which would indicate what the liar did or did not do.

These linguistic analysis softwares have also been used to great effect in identifying the truthfulness of online dating profiles and customer reviews.

00:48:33 The Criteria-Based Content Analysis operate under the assumption that true stories contain certain criteria, and that you can assess the reality of a person’s narrative by considering the accuracy of the elements of the story such as:

  • The amount of detail in the narrative
  • The amount of unusual and superfluous details
  • The accuracy in which the details fit into the timeline and location
  • The amount of verbatim conversation
  • The amount of subjective feelings included
  • The amount of self-depreciation
  • The amount of memory lapses and spontaneous corrections to the narrative

This form of analysis may be manipulated through coaching.

[EDITOR’S NOTE: In his book Redirect: Changing The Stories We Live By, Timothy D. Wilson explains how story manipulation can be used to great effect in helping make people’s lives better, such as with solders who suffer from PostTramautic Stress Disorder (PTSD).]

00:50:22 Skilled interrogators prepare and ask questions designed to increase the cognitive load of the liar, thus increasing the chances of procuring a confession; techniques such as:

  • Asking the person to re-order the events of their story
  • Asking unexpected questions to confuse and throw off balance a liar with a well-prepared story
  • Requesting sketches and explanations of people and locations which can then be verified for accuracy
  • Asking the person to tell the story from a different perspective, such as from the security camera in the corner of the room
  • Strategically using available evidence to increase the pressure, such as withholding facts until in the interview when they can be used to disprove the person’s story