Forensic Psychology Final Exam Revision
Questions Fully Solved
The Polygraph Description - Answer Physiological measures used for centuries
- Dry rice powder
Polygraph based on belief that deception leads to physiological change
• William Marston
- Not a Lie Detector!
The Polygraph Measures - Answer Respiration
Heart Rate
Sweating
Polygraph Uses - Answer - Helps in criminal investigations (suspect)
- Verify a crime has occurred (victim)
- Insurance companies (verify claim)
- Monitoring sexual offenders on probation (United States)
- Pre-employment screening (police, CSIS, etc.)
Types of Polygraph Types - Answer Relevant / Irrelevant Test
Comparison Question Test
Concealed Information Test
Relevant / Irrelevant Test - Answer asks relevant question, then asks question irrelevant to crime
- Larger physiological responses to relevant questions indicates deception
,- Only used for employee screening, no longer used bylaw enforcement
Comparison Question Test - Answer Asks questions:
Irrelevant
relevant
comparison
Begins with two stages:
Examiner stresses polygraph is accurate
Comparison questions are developed
Comparison questions: Designed to provoke anxiety.
Problems with Comparison Question Test: - Answer Innocent may fail
Guilty may pass
Concealed Information Test - Answer - Does not assess deception
- Knowledge about details of the crime
- 10 Multiple choice questions
- One Correct Option
How Does it work - Concealed Information Test - Answer Assumes only someone with knowledge of
crime will recognize the correct answer
Suspects who consistently respond to critical items are assumed to have knowledge of the crime
Not used often in Canada or United States
, Accuracy of Polygraph - Answer Guilty - True Positive
Not Guilty - True Negative
Inconclusive - False Positive
Inconclusive - False Negative
Admissibility of Polygraphs - Answer - Not admissible into evidence in Canada
- Admissible in some states in the U.S
Can Psychopaths Beat the Polygraph? - Answer Psychopaths are not able to beat the polygraph in lab
studies
Can you beat the polygraph with anti anxiety meds? - Answer Polygraph examiner able to tell if
respondent on drugs
Is the Polygraph a lie detector? - Answer Not a lie detector
Issues with polygraph: - Answer Dependent on questioning techniques and interviewee's beliefs
Innocent may fail
Guilty may pass
Event-related brain potentials (ERP) - Answer Brain-based measures:
-Event-related brain potentials (ERP)
- P300 used to detect guilty knowledge
- Research & practical limitations
Questions Fully Solved
The Polygraph Description - Answer Physiological measures used for centuries
- Dry rice powder
Polygraph based on belief that deception leads to physiological change
• William Marston
- Not a Lie Detector!
The Polygraph Measures - Answer Respiration
Heart Rate
Sweating
Polygraph Uses - Answer - Helps in criminal investigations (suspect)
- Verify a crime has occurred (victim)
- Insurance companies (verify claim)
- Monitoring sexual offenders on probation (United States)
- Pre-employment screening (police, CSIS, etc.)
Types of Polygraph Types - Answer Relevant / Irrelevant Test
Comparison Question Test
Concealed Information Test
Relevant / Irrelevant Test - Answer asks relevant question, then asks question irrelevant to crime
- Larger physiological responses to relevant questions indicates deception
,- Only used for employee screening, no longer used bylaw enforcement
Comparison Question Test - Answer Asks questions:
Irrelevant
relevant
comparison
Begins with two stages:
Examiner stresses polygraph is accurate
Comparison questions are developed
Comparison questions: Designed to provoke anxiety.
Problems with Comparison Question Test: - Answer Innocent may fail
Guilty may pass
Concealed Information Test - Answer - Does not assess deception
- Knowledge about details of the crime
- 10 Multiple choice questions
- One Correct Option
How Does it work - Concealed Information Test - Answer Assumes only someone with knowledge of
crime will recognize the correct answer
Suspects who consistently respond to critical items are assumed to have knowledge of the crime
Not used often in Canada or United States
, Accuracy of Polygraph - Answer Guilty - True Positive
Not Guilty - True Negative
Inconclusive - False Positive
Inconclusive - False Negative
Admissibility of Polygraphs - Answer - Not admissible into evidence in Canada
- Admissible in some states in the U.S
Can Psychopaths Beat the Polygraph? - Answer Psychopaths are not able to beat the polygraph in lab
studies
Can you beat the polygraph with anti anxiety meds? - Answer Polygraph examiner able to tell if
respondent on drugs
Is the Polygraph a lie detector? - Answer Not a lie detector
Issues with polygraph: - Answer Dependent on questioning techniques and interviewee's beliefs
Innocent may fail
Guilty may pass
Event-related brain potentials (ERP) - Answer Brain-based measures:
-Event-related brain potentials (ERP)
- P300 used to detect guilty knowledge
- Research & practical limitations
