Lie Detection

• Develop skills in reading non-verbal “tells”• Describe the non-verbal cues • Identifying the most “honest”

part of the body• Know how to detect deception

How We Learn?Answer the following questions below:• What are the 5 senses?• What % of sensory information

we perceive?

How do we learn?Five Senses

• Sight• Hearing• Smell• Touch• Taste

Percent of Information• 83%• 11%• 3.5%• 1.5%• 1%

Where do you look to see non-verbal clues?

• Arm• Face• Hand & Finger• Leg & Feet

Non-verbal cues of the Arm

Arm• Arms up• Open arms

• Arm behind back• Folded arms

• Arm over chair• Arm around

someone

What does it tell you?• Happiness, positive,

joy• Welcome, comfort,

kindness• Superiority• Anger, defensive,

protecting• Confidence• Protective

Non-verbal cues of the Face

Face• Direct eye contact• Avoiding eye

contact• Raised eye brown• Biting lip• Lip licking• Face blush

What does it tell you?• Positive message• Message is not

important • Surprise, disbelief• Nervous, Anxious• Nervous• Stress

Hand & Finger Non-Verbals

Hand & Finger• Resting face in hands

• Hidden hands• Hand shake • Open hand

• Rubbing hands

• Face touching

What does it tell you?• Genuine interest or

boredom• Dishonest• Strength • Honesty, Acceptance,

Sincerity• Concern and

Nervousness• Low Confidence

Leg & Feet Non-verbal cues

Leg & Feet• Bouncing feet• Leg crossing

(standing)• Leg crossing (seated)

• Shoe dangling

What does it tell?• Happy, elated• High comfort• Leg direction

indicates emotion • Comfort

The picture below shows what emotion?

A. HappinessB. AngerC. SuperiorityD. Love

[Default][MC Any][MC All]

James is interviewing for a job with your company. Based on his appearance , James is an honest person.

A. TrueB. False

How to detect deception?

• Nervous fingers• Sweaty palms and faces• Eye contact shifting • Variations in rate of speech• Rigid posture

Is the person below deceptive?

A. YesB. No

Is the person below Deceptive?

A. YesB. No

Visual Cues• Up and left (Visually constructing

images)• Up and right (Visually

remembering images)• To the left (Auditory constructed)• To the right (Auditory

remembering)

Eye Movement

The Person below is Lying.

A. TrueB. False

The Person below is lying.A. TrueB. False

History of Lie Detection• Greeks would ask questions and

“feel the subject’s pulse.”• Torture as a means of interrogation• In 1948, following the horrific

abuses of World War II, the General Assembly of the United Nations inserted the prohibition against torture in the landmark Universal Declaration of Human Rights

• The Supreme Court in 1963 ruled that a confession extracted under “truth serum” – drugs such as sodium pentothal, sodium amytal, and scopolamine - violated a defendant's constitutional right against self-incrimination.

Current MethodsModern polygraphy: uses physiological changes in the

peripheral nervous system (PNS) measure deception

Facial Micro-expressions (developed by Paul Ekman)

“Neurotechnological Lie Detection” (NTLD):

Advantages over polygraph testing: • Fear or other strong emotions may affect

physiological responses and thus may confound the data in polygraphy.

• Polygraphy requires trained experts to read the graphs, while NTLDs would only require computers.

What is the validity of lie detectors?United States v. Scheffer (1998):

• A host of studies show that polygraph testing shows 85% to 90% accuracy while critics state that it is 70%.

• More likely to show innocent people guilty than vice versa. 1. False positive Leads to an incorrect accusation against the communicator. These may be more serious than false negative. 2. False NegativeThe "liar" gets away with the lie. This has been the traditional focusfor assessment of the accuracy of a communication.

• “Polygraph tests can discriminate lying from truth telling at rates well above chance but well below perfection.”

• There is not a 100% accurate way lie detection method

But most importantly… Always tell the truth!

You’re Detective Poly.1. Start with invasive CONTROL questions to begin to

recognize his/her regular behavior.YOU: What class do you have tomorrow?YOU: Who is your favorite musician? What’s the favorite

concert you have ever been too?YOU: What restaurants do you recommend? What kind

of food do they serve?2. Now lets get to the truth!! Here are some

suggested ?s…Feel free to ask different ones, but the key is to probe.

YOU: Have you ever lied to your best friend? What did you say to them?

YOU: Where were you born? What was the name of the hospital?

YOU: In the past month, have you deliberately not answered someone’s phone call? Who was the person?

3. DID HE/SHE PASS BASED ON WHAT YOU KNOW?

You’re Suspect Suspicion1. You will be asked a set of control

questions first that you must answer truthfully for the experiment

2. Let the lying begin! (Note: You may answer all of the questions right or all wrong if you want. This might throw Detective Poly off.)

3. Evaluation from Detective Poly

Now we are going to test your skills……

Read over the introductory lab