1. Truth and Deception Detection
Psychology and the Law
Truth and Deception Detection

2. Plan for Today Class experiment data Video Deception detection
Interviewing

3. Manipulation Check Anxiety Scale
Mean
Std.
Dev. F
significance
Control 20
34.45
8.697
14.574
.000
Anxi-ous
48.5
13.972
Total 40
41.47
13.512

4. Dependent Measure N Mean Std. Dev. F significance Control 20 8.2 3.259
4.217
.05
Anx-ious
5.8
2.267
Total 40
6.92
4.334

5. Lie Detection Eckman (1985) Telling Lies
“lying is when one person intends to mislead another, doing so deliberately, without prior notification of this purpose, and without having been explicitly asked to do so (p. 28)”
“Brokaw hazard”
The Leakage hypothesis – can detect deception by observing ways in which physiological responses are inconsistent with verbal accounting

6. Lie Detection Polygraph Statement Analysis – (SVA , CBCA)
Behavior Analysis
facial expressions
Eye movement and Neurolinguistic programming
Eye contact
Body movement
Voice
Brain scan

7. Polygraph
Truthfulness is more dependent on situational contexts than on a general trait of honesty
Based on autonomic arousal system
S.C.C. (1987) ruled polygraph inadmissable

8. Statement Analysis Statement Validity Assessment
Helps to distinguish truthfulness of witnesses, particularly children in sexual abuse cases
Open ended interview (taped)
Criteria-Based Content Analysis reality criteria (e.g., detail and context)
Validity checklist (e.g., age appropriate language, motivations)

9. Voice Analysis Spectrogram - voiceprint analysis
Voice stress and micro-tremors in speech pattern
Deception is correlated with more speech disturbances, slower rate of speech, higher pitched voice, longer latency to answer
Not legally accepted or scientifically established

10. Non-Verbal Behavior Non verbal leakages are harder to conceal
Facial expressions don’t match the context
Decreases in limb movements are indicative of deception

11. New Measures of Deception
Brain Scan
Memory Scan
Facial Blood-flow

12. Police Interviews With witnesses vs. suspects
Memory enhancement procedures – e.g., Guided Memory Technique, Structured Interview
Cognitive Interview (Enhanced)
Guided imagery
Temporal order
Report any related matter
Recall using different perspectives

13. Interviews with Suspects
80% of criminal cases solved by confession
False confessions account for the most wrongful convictions next to eyewitness misidentification
Torture vs. Soft cell
brainwashing

14. False Confessions Voluntary false confession
– protection, reward, alibi, fear, fame
Coerced-Compliant false confession
– escape or reward (instrumental reasons)
Coerced-Internalized false confession
- creation of false memories