This document summarizes research on deception detection. It finds that people are generally poor at distinguishing truths from lies, correctly identifying about 54% of statements. There is a "truth bias" where people assume statements are true, and deception is detected better for accusations than denials. Training does not usually help detection and people are overconfident in their abilities. Studies found women are more transparent speakers than men. The best cues of deception come from a speaker's tone and language, not physical cues like eye contact or fidgeting that people commonly focus on. Strategies like disrupting or confronting a witness can increase their transparency.

1. “He Said What?”
Deception Detection in Litigation
Edward P. Schwartz, Ph.D., M.S.L.
DecisionQuest
Presented to the LCA Renaissance Symposium
December 5, 2014

2. Will Jurors Believe a Witness?
“My guy is a
really credible
witness.”
“The jury is
going to see
right through
her.”
“He is so
obviously full
of B.S.”
“My expert
comes across
like a Boy
Scout.”
“She presents
as very
earnest.”
“What a
slimeball!”

3. How well do people differentiate truth from lies?
Standard methodology:
Create a situation where some speakers are motivated to lie (or exploit pre-existing
ones)
Expose listeners to an equal mix of true and false messages.
Ask each listener to identify each message as true or false.
Meta-analyses
Aggregate results across hundreds of studies
Analyze data for statistical effects of speaker, listener, message and
environmental characteristics

4. How well do people differentiate truth from lies?
Baseline success rate in studies where ½ of messages are lies:

5. Digging Deeper
Truth Bias
Respondents typically identify about 2/3 of statements as being true.
Myriad cultural, anthropological, evolutionary reasons why truth bias would
evolve.
Correctly identify about 65% of true statements.
Correctly identify only about 44% of lies.
Lie Bias
When statements are denials, there is a lie bias instead.
Important implications for trial strategy.
Accusations generate suspicious minds

6. In Search of Human Lie Detectors
Professionals do not perform any better than ordinary folk.
Psychologists, law enforcement, social workers, judges
Most training techniques don’t seem to help.
There are a handful of naturally gifted lie detectors but most
people are quite terrible.
Some training on “micro-expressions” and “leakage” does
improve recognition of hot spots.

7. The Overconfidence Problem
We generally believe we are better at discerning truth from
fiction than we actually are.
Those who believe they are good at is aren’t any better than
those who don’t. (Correlation: 0.04)
This is a recipe for a false expert to hijack your next jury.
Somewhat akin to the witness ID problem.

8. Have we been looking at this backwards?
Demeanor vs. Transparency
Maybe the action is on the speaker side of the equation.
Subsequent studies showed much more variance in how
easily speakers were read than how accurately listeners
identified deception.
Some speakers were misread over 80% of the time while
others were pegged correctly over 90% of the time.

9. Talk about a gender gap!
Male Listeners Female Listeners All Listeners
Speaker Correct Incorrect Correct Incorrect Correct Incorrect
Lying Men 26% 74% 25% 75% 25% 75%
Truthful Men 46% 54% 55% 45% 53% 47%
All Men 37% 63% 41% 59% 40% 60%
Lying Women 57% 43% 54% 46% 55% 45%
Truthful Women 76% 24% 84% 16% 81% 19%
All Women 67% 33% 68% 32% 67% 33%
All Liars 42% 58% 41% 59% 41% 59%
All Truthful 60% 40% 69% 31% 67% 33%
All Speakers 52% 48% 55% 45% 54% 46%

10. Takeaways from Gender Study
Women are:
Trusting (truth bias)
Transparent (especially when truthful)
NOT simply credible
Men are:
Somewhat less trusting
Opaque (both as liars and truth tellers)
Descriptively Deceptive

11. Why are we so bad at this?
The problem is that we focus on all the wrong cues:
• Eye Contact
• Nervousness
• Blinking
• Laughter
• Hesitation
• Fidgeting

12. Auditory and Visual Cues of Deception
(Zuckerman, DePaulo and Rosenthal, 1981)
Transcript Only: 0.70 Tone Only: 0.20
Entries are in Standard Deviation Units
Visual Cues
Face/Body
Face/No
Body
No
Face/Body
No Face/
No Body
Means
Auditory
Cues
Speech 1.00 0.99 1.49 1.09 1.14
No Speech 0.35 0.05 0.43 0.00 0.21
Means 0.68 0.52 0.96 0.54 0.68

13. Strategies to Increase Witness Transparency
• Disruption
• Distraction of the witness
• Distraction of the Jurors
• Focus on language
• Multitasking
• Confrontation regarding veracity
• Test the witness in advance