The Polygraph Theory

In this experiment we used a polygraph, which examined heart rate, respiratory rate, and electrodermal activity (EDA), and tested its ability to perform as a reliable lie detector. Physiology data such as skin conductance, blood pressure, heart rate, and respiration can be utilized in polygraph tests (Lewis and Cuppari 2009). A polygraph measures the changes in physiological measures, or arousal, to a set of questions given to the participant. There are two main types of questions utilized during a polygraph: The Control Questions Test (CQT) and the Guilty Knowledge Test (GKT). The CQT usually has a subject, in most cases a suspect in a case or criminal, is asked two sets of questions, control questions and relevant questions. Within criminal

The principle on which the lie detector works is that certain involuntary physiological changes occur within the body when a person is lying. The theory is that when a person lies, the lying causes a certain amount of stress that produces changes in several involuntary physiological reactions (Nickell &Fischer, 1999). These changes are picked up and recorded by sensors attached to the body. The polygraph computes changes in breathing, blood pressure, pulse and perspiration; pens record the data on graph paper. The individual is

In the data-collection phase, the examiner will complete polygraph charts, the charts and questions will vary depending on different cases. The examiner then analyzes the collected data in the data analysis phase. The examinee then has the opportunity to explain or rationalize answers to different questions asked during the exam. Although some may criticize the polygraph tests, advances in technology, and science improves the polygraph exams. Multiple factors play a key role in the accuracy of a polygraph, including the experience of the examiner, the obediance of the examinee, and the way the exam is constructed. It is important to consider body language when interviewing examinees as well. This includes things that examinees may be saying, how they say it, and when they say it. One’s body does things that it cannot control, both inside and out, which plays an essential role in exams. When a polygraph test is administered perfectly, and appropriately the accuracy rate is above ninety percent. On the other hand, false positives on the polygraph exams may happen. A good examiner will try to identify, and get away from false positives. When Ruby has a false

of the lie detector in criminal investigation. John Larson, a “college cop”, student of Vollmer, who built the first lie detector in the Berkeley department, later said that he felt the technique had

In 1921 the first lie detector was built. It was used for police interrogations and investigations. It shows the amount of stress that a person releases

“Testimonials during court hearings are performed under oath, hence the statements of an individual being examined are assumed to be true and no other statement should be falsified or forged. When the officer does not pronounce the truth in court, he or she is still capable of providing a reason for his deception, based on a substitute arrangement, such as when he or she is operating as a witness to the prosecution and is not considered as the defendant in a court case. However, it is also required that the officer is conscious of the rules of the court system that he or she has sworn to tell the truth during examination” (Chevigny , 1969).

As a way of being polite, it is unwise to confront someone publicly when you detect a lie in their statement. However, is very important for people to know when someone is lying to avoid eventually getting hurt, or for public safety and security. Detecting lies from a terrorist who is being interrogated has become of essence following the increase in fatal cases due to terrorist attacks such as that of September 11, 2001. Movies production studios and television stations started making films about the use of lie catchers to sense when a person being interrogated is lying. However, some individuals have been witnessed to be having the ability to control their bodies to avoid detection use lie detecting gadgets. The ability to fake emotions and control them to make people believe when someone is lying is called behavioural countermeasures (Carolyn & Mark, 2011).

Section 3. When there is conflict of testimony, each party will be subject to a polygraph test to establish a more likely chance of determining which party is telling the truth.

Credibility- Now, I would like to consider myself an expert lie detector, but apparently binge-watching 12 seasons of Criminal Minds in 3 months does not give me those qualifications. So to better inform and assist you, my lovely audience, I did some research, mostly utilizing online materials.

Polygraph- an electronic instrument Taft records physiological arousal from multiple channels, it is often used as a kid detector the signals are kicked oh by denies attached to different parts of the body. Rubber tubes are strapped around a suspects torso to measure breathing, blood pressure cuffs are wrapped around the upper arm do measure pulse rate abs electrodes ads places on fingertips to record sweat-gland activity or perspiration these signals are send by amplifies and can be seen usually it's to detect deception. But not full-proof sometimes truthful people fail the test and people who understand the test can fake the

Then I read the article called Lies that Fail by Paul Ekman and Mark G. Frank (Ciulla, Martin & Solomon, 2014, p.61) which discusses the ways to detect lies and ways that the truth would leak out of a lie. Which led me

My first reason for these tests not being accurate is because movement could possibly change your results. Have you ever heard someone tell the other person to “stay still” during a polygraph (lie detector) test? Well, this is why. Apparently, if you make the tiniest bit of movement, it could change your results completely! (Shocking!) Why trust a test that has results change as you move? Also, if you move, there is not a guarantee that the results will change. That means, they can’t always just take the opposite of your results when you move.

Individuals today lie about hundred times a day, maybe more. Lying is a normal thing in the human mind—but why is it a normal thing. In fact, every individual's conversation they lie about themselves (Meyers). However, Justin Bariso an FBI agent article title “An FBI Agent's 8 Ways to Spot a Liar” introduced that lying is an easy thing to spot, and Justin discuss how there are ways to spot a liar. Bariso states that a liar would ¨open up,¨ and ¨talk quickly,¨ and ¨be repetitive.¨ Lying is a an action because the individual´s embarrassed about the individual's life; therefore, lying can make people protect other from feelings. In the lives of individuals, there are reasons why people lie. Pamela Meyer, in 2011 TED Talk tilted, “How to Spot

I have attached a Sample result, so you can see firsthand what a result will look like. Please keep in mind the sample I included is that of a bad applicant. This provides you with more examples of an applicant's answers that raise red flags. Here at Personnel Evaluation Inc. we also conduct Polygraph examinations, and our polygraphers use the PEP before every examination.

After the primary test to check the attitude and state of mind of the suspect the polygraph examination moves to the actual test. The principal purpose of the machine is to measure the different variations of each the individuals answers the questions. So in order to establish this for each of the suspects Keeler developed several different techniques to measure their emotional responses to the questions. One of the approaches that he administered was the "Slim Test." (CourtTV.com) The test involves the polygraph examiner making the suspect pick one card out a deck of cards and put the same card back in the pile without letting the examiner see it. After the suspect put the card back in the deck the examiner would show the suspect each card one by one. The examiner them would advise the suspect to say no to every card that was shown to him. This examiner would then would analyze the emotional response to each answer given by the suspect. With the information that was collected the examiner would show