Deception Flashcards
What are the two major methods of detecting deception
- Observing and talking to people
- Physiological Techniques (Polygraph and brain measures)
On average how many lies do Americans tell per day
1-2
Behavior cues for lying
- We assume that telling a lie creates a physiological change
- Assume nervous= lying, but that’s not true
- Verbal cues are best for detecting lies
- Speak prompted hand gestures vs rhythmic gestures
DePaulo, Lassiter, and Stone (1982) lying cues study
Message source participants told 4 descriptions to detection participants
- Describe someone you like
- Describe someone you dislike
- Describe someone you like as if you dislike them
- Describe someone you dislike as if you like them
Half of detection participants told to focus on vocal tone
- Produced better truth detection
Verbal cues to lying
- Higher pitched voice
- Speech disturbances
- Slower rate of speech
Content cues to lying
- Liars provide fewer details than truth-tellers
- Liars’ Stories are less compelling than truth-tellers (less plausible, lacking logical structure, more discrepancies, less engaging, less fluent, more nervous, tense)
- Truth-tellers are more likely to spontaneously correct their stories and more likely to admit lack of memory
Adams & Harpster (2008) 911 call experiment
- Analyzed 100 911 calls (50/50 for guilty and innocent)
INNOCENT - Request help
- Corrects misinterpretations
- Rude and demanding
- More emotion in voice
- Quickly speeking
- Cooperative
GUILTY - Irrelevant details
- State victim is dead
- Polite and patient
- Blame or insult victim
- Less emotion in voice
Microexpressions
Brief, uncontrollable facial expressions that reflect the emotion a person is feeling
Paul Ekman’s take on microexpressions
- Believed that certain people were especially good at lie detection
- Narrowed 12,000 professionals down to 29 people who could detect at 80-90%
- Theory was debunked
How were microexpressions studied
- Had nurses watch gruesome medical films and pretend they were pleasant
- Looked to see how they tried to conceal it
- Focused on containing their facial expressions
- Mircoexpressions still visible
Can we reliably detect deception?
- Laypeople detect at a rate of 54% accuracy
- Trained professionals detect at a rate of 55% accuracy
- Secret service are better than others
- Women better at detecting lies than men with people they are close with
Why are we so bad at detecting lies
- People rely on stereotypic beliefs about lying (gaze aversion and fidgeting)
- Truth-bias: People judge more messages as truthful than deceptive
- The differences between truth-tellers and liars are small
High-stakes lies
- Officers are better at catching high-stakes lies
- They are more familiar with settings that involve high-stakes lies
- Lies are easier to detect when the liar is motivated
The Othello Error
Too readily interpreting signs of nervousness as deception
The Polygraph Technique
- Not Admissible in Canadian court
- Polygraph: Device used to record an individual’s autonomic nervous system response (emotional states and arousal)
- physiological states associated with lying similar to those associated with anger, anxiety, embarrassment and fear
- Records beathing rate, heart rate and skin conductance (sweating)
