Detecting Deception Flashcards
What is Deception?
A successful or unsuccessful deliberate attempt, without forewarning, to create in another a belief which the communicator considers to be untrue
What are Physiological Cues to Deception?
- Polygraph
- psychologists tend to ignore this
- not featured in the UK’s justice system
- Breathing
- Heart rate
- Blood pressure
- Sweat
What are Behavioural Cues to Deception?
- Non-verbal
- Verbal
What are Evidential Cues to Deception?
- Physical
- ‘Logical’
- plausibility
- is what you’re saying to me make sense?
- plausibility
How do you detect lies in forensic settings?
Detecting deception has to happen within ‘real-time’:
1. Physiological responses;
2. Observe behaviour;
3. Listen speech;
4. Analyse speech;
What are the 2 approaches to detect deception?
- Cognitive Load/Effort
- Truth Default Theory
What is a Polygraph?
In the test, several pens draw lines on a moving piece of paper under electrical control, determined by electrophysiological responses of the body.
What are the phases of a Polygraph?
- Pre-phase: Gathering information and writing questions
- Phase 1: Pre-test interview
- Phase 2: The test
- Phase 3: The post test
What are the 3 main test questions asked during a Polygraph?
- The Control Question Test (CQT): This test compares the physiological response to relevant questions about the crime with the response to questions relating to possible prior misdeeds. “This test is often used to determine whether certain criminal suspects should be prosecuted or classified as involved in the crime” (American Psychological Association).
- The Directed Lie Test (DLT): This test tries to detect lying by comparing physiological responses when the subject is told to deliberately lie to responses.
- The Guilty Knowledge Test (GKT):This test compares physiological responses to multiple-choice type questions about the crime, one choice of which contains information only the investigators and the criminal would know about.
What are some of the advantages for the Polygraph?
- The polygraph questionnaire usually comprises several sets of questions – inadequacies of any questions can be compensated for by other questions
- Distinction to be drawn between the practical utility of the polygraph and its scientific adequacy – encourages guilty individuals to confess this is an advantage
- Criticisms do not mean that the polygraph is worthless, but that it might need further refining (i.e., the guilty knowledge test).
What are some of the disadvantages for the Polygraph?
- The adequacy of the control questions is key – can be difficult to get these right
- Being accused of an offence is emotive for the guilty and the innocent – can the polygraph differentiate between the guilty and innocent?
- The control questions might disturb the guilty more than the innocent
- Faking and countermeasures are possible – many experts advertise how to ‘fake’a polygraph
- In its practical application, the polygraph has not been subjected to a ‘fair test’ –operator is not blind and it has not been tested against groups of known innocents
- Not the only way a body responds to fear of detection
What is a confession?
A statement admitting or acknowledging all facts necessary for conviction of a crime.
What are some of the reasons to why do people make false confessions?
- Multifaceted
- 2 primary factors
- Variables associated with the ‘situation’ people find themselves in at any point in time – external to the individual
- Variables associated with the individual – Dispositional
What are 2 primary factors to why do people make false confessions?
- Situational variables
- Psychological variables
What is a Primary Situational variable?
- Within a interview or interrogation
- Techniques + Environment + Investigator bias
- 3 types of false confession:
- Voluntary
- Compliant
- Internalized
