Polygraph Techniques Relevant-Irrelevant Test (RIT) Contains nousing questions that are unrelated to the incident "What did you eat for lunch today?" Then contains relevant, arousing questions. "Did you commit the murder?" Assumption, liars will have more arousal during the relevant question. Research has shown high rates of false positives. Makes sense. Even if you didn't commit the crime, obviously you can tell what the critical questions are Even if you're innocent, you may be nervous about coming off as truthful, otherwise you could be arrested. Polygraph Techniques Continued . Comparison-Question Test (CQT):| Designed to improve upon the RIT This is the most frequently used technique Contains a lengthy preamble interview during which the examiner attempts to subtly convince the suspect of the polygraph's ability to detect lies " They may trick the suspect into believing the polygraph is always accurate by asking the questions about the suspect's past and stating if they're true or not based on already having viewed his/her records and information. Relies on the skill and demeanor of the examiner what questions does he/she craft, is he/she intimidating Polygraph Techniques Continued Comparison-Question Test (CQT): Contains comparison questions (aka known lie questions) "Have you ever lied to get out of trouble?" assumed that everyone will lie here and experience some discomfort and arousal over that lie Contains critical questions: "Did you commit the crime?" Assumes innocent people will react more strongly to the comparison question (known lie) than critical question Assumes liars will react more strongly to the critical question than the comparison question. Polygraph Techniques Continued Comparison-Question Test (CQT): The same issues as before are present for this test False positives for innocents who are fearful Some people are non-reactive or controlled Criminals with no faith in the test may not react to the questions. People can use 'countermeasures' Inducing arousal in one's self during control questions And suppressing arousal during critical/relevant questions The judgements of examiners are, just like with forensic evidence, subjective how much difference in heart rate means he/she was lying? Subject to confirmation bias Research on the Polygraph . Professionals may claim accuracy rates of 90-99% Massive meta-analysis (Ben-Shakhar & Furedx, 1990) of 109 well-conducted laboratory studies found that: of guilty suspects accurately classified (good!) of innocent suspects classified as guilty (bad!) Research on the Polygraph. Our justice system operates under the idea that 'It's better to let 10 guilty people go free than one innocent go to prison' You may or may not agree with that . liars Another criticism of these studies is that the stakes are not high enough for the They're just mostly students like you guys who go in to do their Sona studies and are told to do a mock crime Their entire life and liberty isn't on the line call this a threat to external validity Research on the Polygraph The authors are still very much against its use certainly agree it has many flaws But its accuracy rate in that meta-analysis is still somewhat impressive And it certainly is not doing worse than most human lie detectors, since we're about at chance levels or even below chance when investigators look for liars' stereotypes hope would be that it remains "a tool" to use, but it certainly shouldn't be seen as infallible Jurors should see it as moderate-weak evidence Research on the Polygraph the text mentions, one idea for improvement here would be blind evaluators. ne polygraph examiner conducts the session. But then, the suspect's physiological data (changes in heart rate, etc.) would be sent to another examiner who is blind/objective. They could evaluate the changes in arousal based on the questioning and determine if they're big enough to indicate lying Another issue with the polygraph is that its results are often used as an evidence ploy by investigators, contributes to false confessions. Guilty Knowledge Test (GKT) One final technique (my favorite!) Aka concealed information test not looking for lies, it's looking for knowledge of facts For example, you could: Show a variety of photos of houses (with one being where the crime took place) variety of knives (with one being the weapon) ask questions such as: "Where was the body found? In a ditch? In the woods? Dumped in the river? Etc." Assumptions: perpetrator will have more arousal for the key item, but innocent people will not Side note: the first item on the list is always a 'buffer' Research on the GKT meta-analysis of 22 studies (MacLaren, 2001) found that: correctly identifies 82% of guilty suspects And 97% of innocent subjects That's pretty darn good! Limitations of GKT Sufficient number of crime facts must be available Facts must not be widely publicized Details must be recalled by the guilty person Unlikely if drunk, mad, afraid, etc. Applicability to large number of crimes may not accur man said sex was consensual but a woman said it was rape, the GKT does not help here Resistance of professional polygraphers may occur Reduces the part of polygraphing that is an 'art' Legality of the Polygraph states have banned the use of it Others permit it in certain situations. Random Note: While browsing Youtube for videos for today, I saw many people claiming to be lie detection experts. But are they really? you think someone has had them participant in a controlled experiment to measure their accuracy rate? more likely they're just 'snake oil salesmen'/frauds? Discussing Social Psychology should be one of the most fun and rewarding parts of the course. These topics are fascinating and there's always more research or ideas to consider. Each week (except for the last week of the course) you will be responsible for the following: One discussion question and two replies. Discussion questions are due at Friday at midnight of that week, discussion responses are due Sunday at midnight of that week. I would recommend just posting your question as soon as you have read a PowerPoint and something interesting pops into your mind. Better to complete the question early in the week and then reply later in the week, as you read through other interesting questions. And you don't want to be stuck having to generate a question at midnight on Friday. 1. Discussion Question: Create a post with a discussion question. This can be a short post, just a sentence or three, that poses an interesting question. For example, "Based on the material from this week, what additional research do psychologists need to conduct to continue to understand and reduce racial prejudice?" Or "In addition to business meetings and juries, what are some other situations where we could see group decision-making happening in the real world? And what would potential problems could arise during such a meeting?"