Detecting Deception Flashcards
What is lying?
An active process that requires one person to accept a falsehood as truth.
What did DePaulo et al find in their study where they asked people to keep a diary of how often they lied in a week?
1 in 4 social interactions: lied to more than 30% of the people they interacted with.
What did Hancock find their study on where people lie the most?
14% of emails, 27% face to face, 37% of phone calls.
How does the polygraph test work?
Records autonomic arousal and detects physiological states associated with lying
What are the 3 things that the polygraph records?
Respiration (top line)
Galvanic skin response (middle)
Blood pressure (bottom)
What types of lies do polygraphs detect?
One’s that are highly motivated and highly motivated to avoid consequence.
What is the Chinese Rice technique?
Fill their mouth with dry rice and leave them. Then ask them to spit it out. If it’s dry, shows they’re nervous due to having a dry mouth.
When did the modern polygraph originate?
1917
Is the polygraph a piece of admissible evidence in Canada and the US?
Not anymore.
What are some of the uses of the polygraph test?
As a means to resolve a case, police selection, determining if an offender is violating his terms of probation.
What is the relevant/irrelevant polygraph test (older model)?
2 types of questions
1. Relevant questions concerning the crime in question (Did you rob the bank)
2. Irrelevant questions concerning info unrelated to the crime. ( have you ever taken anything that didn’t belong to you?)
Jacks up involuntary responses, no control questions. Compare responses between the two conditions.
How is guilt determined using the relevant/irrelevant procedure?
A guilty person will have a stronger response to relevant questions.
What is the control question test?
Most commonly used with 3 types of questions:
1) Irrelevant question referring to respondents identity
2) Relevant questions about crime
3) Control questions.
What is the control question test designed to do?
Be emotionally arousing for all respondents and typically focuses on a person’s honesty and past history.
What types of responses should innocent people show the largest reactivity to in the control question test?
Control questions.
What types of responses would manipulators show on the control question test?
Similar reactivity on relevant and control (same with anxious people)
What types of responses would criminals show on the control question test?
Relevant questions would show higher arousal than control.
What is the point of having a control question?
Deals with prior behaviour and is designed to provoke anxiety.
What is the point of having irrelevant questions?
To obtain a baseline.
What is the guilty knowledge test?
Seeks to determine whether the suspect knows details about the crime only the culprit would know. Questions are asked in multiple-choice or list format.
What types of physiological responses do individuals show on the guilty knowledge test?
On the answers that are correct to the crime in question- questions with specific and memorable meaning to the perpetrator. Innocent people wouldn’t have this physiological arousal.
What was the case of Floyd Fay?
Arrested for murder, prosecutor offered him a deal: take a polygraph test. If he passed, charges would be dropped. If he failed, a second test would be given. If the results from the second test conflicted with the first, the case would go to trial. If both failed,d then he’d plead guilty to lesser charges. If he refused to plead guilty, he would be tried for the original charge and results from the polygraph would be admitted as evidence. Floyd Fay then trained innmates to cheat the test.
What percentage of guilty suspects are correctly classified as guilty according to CQT studies?
84-92%.
What percentage of innocent suspects are correctly classified as innocent according to CQT studies?
55-78%.
