Attempts to detect lies
• Lie detector
• based on theory, liars are nervous
• pulse rate, blood pressure, respiration, and palm sweat.
• Detects people who are nervous when they lie
• Detects people who are nervous that you aren't going to
believe them
• Works about 70 percent of the time
• MRI brain scan
• Lie is a cognitive activity, not a memory activity
How to tell when someone is lying
General Verbal Responses
• May take longer to start answering
• May answer to quickly or before the question is completed
• Often ask the questioner to repeat the question or they repeat it themselves
• Overly polite or apologetic dialog
• Persistent complaints
• Unnatural silence
The Behavioral Clusters of Deception
• Deceptive people follow certain behavioral patterns.
• - Macro Patterns General Behaviors:
• Increased discomfort and anxiety, hostility, unmerited anger towards you, persistent evasiveness, resistance
• Early signs of extreme rigidity followed by alternating stiffness and relaxation. Hands, legs, objects put in front of body to
form a barrier (folding arms, crossing legs, etc.). Feigned lack of interest. Posture changes caused by topic changes. Not
facing you. Distancing or leaning away from you.
Gestures and Movements:
• Rubbing the forehead near the temple region. Squeezing the face, rubbing the neck, or stroking the back of the head with
the hand. Using fewer hand movements to illustrate their actions than usual. Movement away from you. Lip licking and hard
swallowing. Wringing hands. Hiding the eyes
• - Micro Patterns -expressed on the face
General Expressions:
• Averting the eyes. Focusing the eyes - some will try to stare down to show control. (A truthful person stares only half the
time on average). Face whitening.Face flushing.
Eye-Accessing Cues
• By the direction of where the person’s eyes are looking, you can determine whether they are using vision, sound or
kinesthetic (feeling) to trigger their thinking.
• Keep in mind that this is reversed for left-dominant people (left handers). So before you can use this, be aware of which of
their sides is the dominant one.
Signs That a Person Is Lying
Detecting lies in people you know is FAR easier than
detecting lies in a stranger. When dealing with
strangers, use baseline questions that nobody would lie
about to establish “normal” behavior.
Assuming a person is deliberately lying AND recognizes
lying as negative, you may observe some/all of the
1. Reduced articulation
2. Facial and body responses that do not “match”
3. Facial and body responses that pass quickly are are
replaced by more “conscious” responses
The Scientific Fact
Lies are present in:
37% of phone conversations
27% of face-to-face conversations
14% of emails (Hancock, 2005).
Without training, lies are not easily
Behavior can be misleading in
credibility assessment
Visual Clues
• Numerous studies have been done with subject telling
known lies and telling the truth. Their behavior was
recorded and correlated. The results show some
behaviors is correlated with lying:
• Pupil dilation – Much more pronounced in liars
• Vocal tension – More pronounced in liars
• Vocal pitch - More pronounced in liars
Visual clues
• Fidgeting – No difference
• Blinking – No difference
• Cooperative – More pronounced in non-liars
• Smiling – No difference
• Lip pulls – No difference
• Pleasantness – Barely more pronounced in NL
Visual clues
• Are liars less forthcoming:
• Longer responses – More pronounced in non-liars
• Rich details in story – More pronounced in non-liars
• Rate of speech – No difference
• Time before starting – No difference
Visual clues
• Are stories of liars more compelling?
• Stories have discrepancies/ambivalent – Slightly more pronounced
in liars
• Stories less logical - Slightly more pronounced in liars
• Stories impersonal/distant – Definitely more pronounced in liars
• Uncertainty – Slightly more pronounced in liars
• Word repetition - Slightly more pronounced in liars
Visual Clues
• Foot/leg movements – No difference
• Posture shifts – No difference
• Head/Hand movements – No difference
Visual clues
• Admitted lack of memory – More pronounced in non-liars
• Spontaneous corrections – More pronounced in non-liars
• Unusual details – No difference
How to lie
• The first thing you do when lying is to tell the truth -- not the whole
truth, but just enough to make the lie itself seem true. If you sense that
someone else suspects you of lying, admit to something small or
untrue. Think of some specific true thing (place, person, event, story)
that your lie will fit into and use those details if you are questioned. This
gives you a bank of specific details to draw on so you don't have to
keep making things up as you go along.
The trick is convincing your sub-conscious mind that you're telling the
truth. An example of this may be, "Did I wreck the car? Well, I drove it
into a wall. So, the wall wrecked the car. I just moved it!”
Look the person you are lying to in the eye. Don't look around. Try
making your eyes go big and letting your mouth hang open a little for
an innocent/shocked look.
Never forget about your lie, and treat it like it actually happened.
Mention it in conversations the way you would if it was true. Silence
about a certain subject can arouse suspicion, especially in retrospect.
Use named, recognizable people.