Lie detector operating principle. Is it possible to fool a lie detector? Application in judicial practice

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The need to use a polygraph is becoming more urgent every day, and the point is not that people are starting to lie more. They always tell lies, but many people think that a lie detector is something fantastic, a tool from movies and only intelligence services can gain access to it, which is fundamentally wrong. Nowadays, everyone is able to resort to the services of a polygraph examiner, regardless of for what purpose the person intends to use it and to whom to apply it.

How does a lie detector work?

To understand how the polygraph works, what the subject reacts to, and what results we can get from his answers, it is necessary to understand the very structure of this device. Surely you have all seen in films old models of polygraphs that used ink, special antennae and paper. Thanks to the vibrations of these antennae, the reaction of the human body was displayed on paper, and the readings themselves were then interpreted and appropriate conclusions were drawn.

Nowadays, no one uses analog (ink) polygraphs, since technology makes it possible to use new (digital) models. They differ from analog polygraphs in that the device itself already consists of personal computer, sensor unit and recording sensors. This allows the polygraph examiner to easily pack the machine into a small suitcase and go to the customer’s location.

The results in the polygraph examiner's report are always focused on the client's needs, so you get only the result that you were interested in

To understand how a lie detector works, you do not need to be a scientist, since in fact the principle of its design is quite simple to understand. Since the basis of the polygraph’s operation is the recording of physiological indicators in the human body, the following sensors are connected to it for measurement:

electrical conductivity of the skin - by and large, which is a set of reactions of our skin to irritants. Let's say it has been scientifically proven that sweat production reflects the work of certain parts of the brain and therefore galvanic skin reflexes and skin resistance are an integral component of testing;
cardiovascular activity is simple for us to understand, since it is responsible for pulse, blood pressure, vascular filling with blood, and so on. You yourself understand that the moment a person utters a lie, his pulse automatically quickens, there is more blood in his vessels, and people do not yet know how to block such reactions of the body with their consciousness;
fixation of lower and upper breathing. Even in psychology, the concepts of abdominal and thoracic breathing are distinguished, and by the way a person breathes, certain character traits can be told about him, and so on. Therefore, in testing using a polygraph, obtaining data regarding a person’s breathing is an integral part.

Important! The above list with explanations is presented here in a clear manner for ordinary person form, and the full picture of physiological reactions, the significance of their entire complex, the complexity of the process and other points are too serious and profound to be discussed in this article. Now you roughly understand how a polygraph works, without burdening yourself with knowledge that is smart and not really necessary for the average person.

The relevance of the use of the polygraph.

As noted above, most people still think that a lie detector is something complicated and serious for the average citizen to have access to. We tell you that this is not so and now anyone can use the services of a polygraph examiner. If it is difficult for you to imagine in what cases you can use a lie detector, then think about whether you are sure that:

your business partner conducts business honestly;
your children are not deceiving you and are really good students, do not abuse any kind of substances, does your child have problems that he is afraid to admit;
your wife is not cheating on you or your future bride is not getting married just for the sake of receiving some kind of material gain;
employees in your company perform their duties as efficiently as possible and do not steal.

To get high-quality results, you can always contact our company Stability LLC, where the best specialists in this field work

Reference. The range of testing focus is huge, and in cases where you need to find out the truth, this method can be used; moreover, the customer is able to influence what exactly the test will be, which questions interest him more than others, and so on. The results in the polygraph examiner's report are always focused on the client's needs, so you get only the result that you were interested in, and not the one you considered necessary to provide.

Factors influencing the test result.

Even knowing the principle of operation of a polygraph (lie detector), it is necessary to understand the factors that influence the result of the test, and their list, although small, is important for familiarization.

Education of a polygraph examiner - according to a unified international standard, it is planned to train future specialists on the basis higher education. The duration of training cannot be less than 400 hours, and in the Russian Federation such courses can be taught up to 1,000 hours, and only after successfully passing the exam a person will be able to receive a polygraph examiner diploma. It is the level of education that is the key factor in testing.
Erroneous interpretation by a polygraph examiner - since the lie detector measurement is not the lie itself, failure by the specialist to follow the available techniques can lead to an incorrect interpretation of the obtained physiological indicators, which will give erroneous conclusions.
Prejudice of the person being tested and the polygraph examiner himself - a person’s belief in what he says may be true for his body, even if this information is not true, so the reaction is not always displayed as it really is. A polygraph examiner, having a biased attitude towards a person, cannot examine him normally, since he will draw conclusions based on his prejudices.
The state of the person being checked - at this point everything should be clear. The accuracy of the results of polygraph testing cannot be accurate if the subject has mental disorders, health problems, especially in the areas recorded by the device, if the person takes pills or has not reached the age of 14-18 years.
Counteraction - it is argued that there are a number of special techniques by which a person is able to influence the polygraph readings, unnoticed by the polygraph examiner.

Accuracy of results.

There are still ways that lead to ambiguity in the results obtained, since nothing is ideal in our world. But we hasten to assure you of the following: only 5-7 people out of a hundred manage to pass the test in such a way that its results are “incomprehensible”. That is, in such cases we cannot claim that the results are completely accurate, but this in no way means that the polygraph examiner was deceived. Repeated testing usually helps in such situations. Speaking in percentage terms, the accuracy of the detected data is 93-95%, which is a high figure, sufficient even for the reports of polygraph examiners in courts to be evidence of innocence.

Now you know not only how the polygraph works, but also understand exactly in what cases you may need this type of testing, what result you will get, and decide for yourself which identified aspects are more important to you. To get high-quality results, you can always contact our company Stability LLC, where the best specialists in this field work, who have proven their skills over years of impeccable work.

Any person who receives an offer to take a lie detector begins to worry, look for information about what a polygraph is and how to pass it, what can await him as a result of such testing. Let's figure out why a polygraph test is carried out and how to properly prepare for it.

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What is a polygraph

Polygraph – technical device, used for fixation psychophysiological reactions a person that arises in response to questions presented to him - stimuli.

Attention! In ordinary life, many people call the device a lie detector.

The procedure is carried out by a polygraph examiner - a specialist who has special education in the field of conducting research using a polygraph.

The main objective of the examination is to establish the reliability of the information provided by the person being assessed to the polygraph examiner.

Polygraph

When is the inspection carried out?

The popularity of polygraph tests is growing, and the scope of their application is actively expanding. Businesses are beginning to increasingly use this tool, trying to reduce their risks when hiring employees who can cause significant damage to the employer.

Most often, this method of assessing the reliability of information applies in the following cases:

Screening candidates when hiring.
Regular assessment of the organization’s operating personnel in order to monitor compliance with requirements, concerning safety business.
Checking employees if the enterprise an incident occurred: material assets, information leakage to competitors, receiving kickbacks.
In the judicial system conducting investigations.
In personal relationships, when, for example, family members want to check how honest they are with each other.

Polygraph test

Is the inspection legal?

Russian legislation does not prohibit conducting polygraph examinations, so there is nothing illegal in the offer to undergo them. But anyone can refuse them. And everyone who agrees to undergo polygraph testing signs voluntary consent.

Whether to refuse or not depends on how interested the person is in this procedure. Having rejected an offer, for example, when applying for a job, the candidate may lose chance get the job you want because the employer can conclude that the applicant has something to hide. He cannot refuse a candidate on this basis, but choosing another is his right.

When verification is not carried out

There are cases when it is really better not to take a polygraph test and refuse it yourself. This is especially true for situations where there is an understanding that the results of the decision are unlikely to be positive, since there is a need to hide something.

Polygraph testing is not carried out in relation to a certain category of people regardless of whether they are ready to go through it themselves or not.

Testing will not be held, If:

age of the subject less than 14 years old;
have mental illnesses and disorders;
there are signs of physical and mental exhaustion: fatigue, chronic lack of sleep, prolonged stress;
the subject takes strong drugs;
the person is sick with cardiovascular diseases or has problems with the respiratory system;
alcohol or drug intoxication was detected;
a woman is expecting a child, especially in the second half of pregnancy.

The polygraph examiner will definitely clarify the questions regarding the existing restrictions, and therefore you need to respond to them absolutely calmly. He asks about this not because he wants to convict someone of something, but on the contrary, he strives not to do harm, since all the listed cases relate to the possible receipt of an unreliable examination result.

The polygraph examiner is obliged to clarify questions regarding existing restrictions on testing

The principle of operation of a lie detector

Polygraph is technical device, which does not evaluate anything, does not make a verdict. Its task is to record a person’s physiological reactions to questions and at the moment of providing an answer to them. Any emotion is always reflected in physical level: sweating, change in breathing or pulse. It is these indicators that detector will detect.

A polygraph is a complex consisting of several parts:

Sensors that measure blood pressure, pulse, respiration and sweating.
A device that registers signals coming from sensors and then transmits information to a computer.
Computer with specialized software m, evaluating the resulting reactions. As a result, the program generates a graph - a polygram, which shows all the changes occurring in a person.

At the end of the examination, the polygraph examiner will analyze the polygram and prepare a conclusion with the results of the assessment.

The questions asked are based on special questionnaires– tests necessary to verify the reliability of information provided to test takers on specific research topics.

How is testing carried out?

Polygraph testing consists of from several stages.

Meeting and getting acquainted with a polygraph examiner.
A preliminary conversation in which the purpose of the inspection will be explained and the procedure will be explained. It is important to know that all questions that will be asked will be discussed. Until the polygraph examiner is convinced that the test taker knows and understands all the test questions, he will not begin the procedure itself.
Human signs consent to pass the test or refuse.
If you agree, the testing phase begins. First, detailed instructions are given: how to behave, what not to do, sensors are put on, and questions are asked.
During the tests, the polygraph examiner may have additional questions in connection with the reactions of the test taker. In this case, a second conversation is conducted, the information is clarified and changes are made to the test questions, and the test continues.
At the end of the procedure, the polygraph examiner releases the person being tested and processes the results obtained, prepares a conclusion.

Is it possible to fool a lie detector?

For as long as the polygraph has existed, the question of whether it can be deceived has been discussed for so long. Experts believe that this can be done almost impossible, and among non-specialists there are a considerable number of people who believe that this is very easy to do.

Further more. On the Internet you can find advice on how to pass a lie detector and deceive it, and even describe ways in which this can be done. You can even find offers to take a lie detector test online.

When studying recommendations on how to pass a polygraph without problems and deceive the detector, it is important to remember that it does not pay any attention to words or facial expressions. It records reactions that occur in the human body and are a consequence of the work of the brain. Those who learn to control their own reflexes, then will be able to deceive polygraph.

Any method used by the test taker to bypass the polygraph is countered by polygraph examiners.

Can follow recommendations: take pills, don’t get enough sleep, don’t think about anything while answering questions, concentrate your attention on the flower standing on the windowsill. However experienced specialist He will immediately see this and will treat the test results very carefully.

Separately, it is necessary to note the proposals to test yourself by taking online lie detectors. Essentially, this is a psychological test that determines emotional stability. And on this basis, the probable possibility of deceiving the detector is calculated.

To trust such results or not, to use or refuse the proposed methods to deceive the polygraph is everyone’s personal choice.

How to pass a polygraph when applying for a job

The offer to undergo a screening test when applying for a job may come as a surprise to many. Almost everyone begins to get nervous about this topic, and many perceive such information as an insult to their honor and dignity. But if we assume that the candidate himself was an employer, and he had a chance to weed out those who could potentially threaten the business on which so much time and effort was spent, would he refuse such an opportunity? The question is rhetorical, and the employer can also be understood.

Important! Concealing the truth is the main reason why the result may clearly not be in favor of the person being tested.

There are several factors capable of influencing on the test result.

Nerves, excitement, anxiety with which the candidate goes to the procedure. An experienced polygraph examiner will note this, and if for some reason he is unable to relieve the applicant’s excessive anxiety, then he can refuse to carry out check.
Taking sedatives before testing will slow down the reactions, which will be noted by the specialist. It's better not to do this.
Illness or general poor health will affect the result. If physical state deviates from the usual, or is bothered by pain, then you need to warn about this, and the procedure will be rescheduled for another day.

Passing a polygraph test when applying for a job

How to behave during an inspection

The main thing is to know how to behave during the test. The first thing is to get your nerves in order. And then follow everyone polygraph examiner's recommendations. You shouldn’t be afraid of him, you need to answer questions, try to explain to him as accurately as possible your reactions to them during a conversation between tests.

The worst thing you can do is — this is to start interfere with the examination: spinning in a chair, pressing on sensors, answering test questions in a few words instead of an unambiguous “Yes” or “No,” showing negative reactions to questions, being indignant. It's better to refuse right away.

For those who need to go through the detector for the first time, we can recommend taking into account some tips how to behave:

Do not plan urgent matters on the day of the polygraph test. The procedure may take a long time for 2-3 hours.
Try to be honest. The more truthful answers are given, the better the results will be. Remember that there are no absolutely honest people. If you have nothing special to hide, then there is nothing to fear.
Do not try to disrupt the test by not following the polygraph examiner’s recommendations. It's better not to come to it at all.

Useful video: how is a lie detector test performed and is it possible to fool a polygraph?

Have you ever deceived your loved ones? Have you ever taken something without asking? If you answered “Yes” to these questions, then you have already taken the first correct step towards passing a lie detector test.

History of the creation of the polygraph

Since ancient times, humanity has been worried about the question: “Is this person telling the truth?” The answer to this question was, is and will be very important for the following reasons:
- can we trust this person?
- can we trust the information received from this person?
- How correct will be the decision made on the basis of the information received?
- will the person achieve his goals?
- Is this person guilty of what happened?

At different times there were different methods obtaining truthful information. At the dawn of human development, these were mainly methods physical impact and gross psychological violence. It's hard not to tell the truth when you're being crucified on the rack!

It's difficult, but it's possible! History knows of cases when the tortured never told the truth. However, from the point of view of effectiveness, the methods are quite effective, but only in relation to the culprit. If a person is not guilty, then, often, unable to withstand torture, he took the blame upon himself, which, from the point of view of analyzing methods for obtaining truthful information, made the use of torture and similar methods completely meaningless. And the most significant disadvantage of these methods is that they are not acceptable from the point of view of human morality: after torture, a person remained disabled and often died.

As soon as psychology was born, as the science of behavior and processes in the human psyche, psychologists began to analyze and identify signs that clearly indicate that a person is lying. What has not been suggested as such signs?! Does he look away during a conversation? Are your hands shaking? Are there red spots? Liar!

But over time, psychologists developed an understanding that there are no one or two signs with 100% probability that indicate whether a person is lying or not.

In the middle of the last century, a breakthrough occurred in this issue, when several parameters of the life activity of a person telling a lie were analyzed simultaneously. It turned out that a lie, as it were, forms a kind of “hotbed” in the brain, which has a complex effect on the human body on a subconscious level. That is, the body of a person who is telling a lie cannot simultaneously control changes in many indicators of its vital activity. If you can suppress the trembling of your fingers and changes in breathing, then you don’t have enough “strength” to control your blood pressure. What if you also measure your pulse?!

This discovery of psychologists formed the basis for the creation polygraph(“poly” - a lot, “graph” - I write, lat.) - a device that simultaneously records several physiological parameters of a person. And based on an analysis of changes in all parameters, a polygraph examiner can with a high probability conclude whether the person being tested is lying or telling the truth.

How does a polygraph work?

Modern “lie detectors” can simultaneously take and record up to 10 vital signs of the body. Starting with classic measurements of pulse and pressure, and ending with measurements of galvanic skin response and changes in voice timbre. In this case, the device automatically analyzes these indicators and signals the polygraph examiner about their changes, calculating the degree of “sincerity” of the person being assessed.

How does a polygraph test work?

Modern procedure polygraph testing differs significantly from medieval "torture chamber" methods. The test should be carried out in a quiet room with a neutral environment in which the test person’s gaze does not “catch”. Before the test, the specialist needs to communicate with the subject, telling him about what is happening. He should tell you in sufficient detail about the topic of the interview, the questions asked and the testing procedure. As a result of communication, the test taker should calm down and be constructively disposed to the test. It is not allowed to check a person who is under the influence of alcohol or drugs, or who is behaving emotionally inappropriately.

For several minutes, the polygraph examiner writes down the parameters measured by the polygraph on the computer in silence, as if “calibrating” the machine. Then, in a calm, non-emotional tone, he reads out the questions that interest him, to which the subject must calmly answer “yes” or “no.” If on asked question If there is no definite answer, then the test taker calmly informs the polygraph examiner about this. In this case, the polygraph examiner must reformulate the question so that the answer is either “yes” or “no.”

On average, the entire testing procedure takes from one to two hours. Depending on the type of test, the test results are communicated to the person being tested immediately or transferred to the initiator of the test in any way convenient for him.

Where is the polygraph used?

Currently, the lie detector has ceased to be a tool only for the intelligence services. With its help, not only internal investigations and emergencies that occurred in commercial organizations are carried out (information leakage, theft and fraud), but also personnel screening checks (when hiring), certification checks of working employees, as well as checks on everyday issues (suspicions) are carried out in treason, checking teenagers for various types of abuse, etc.)

The polygraph sales market is also growing every year. Almost every large company has a polygraph examiner on its staff, who is hired to carry out the above-mentioned checks of working personnel and job candidates.

But if the organization’s staff is not very large, then it is more profitable to invite external company. This is called personnel security outsourcing. Such companies are the main activity of AIC Detector. The second most important area of activity for us is identifying those responsible (and protecting those not guilty) in thefts and thefts.

Polygraph accuracy

One of the most popular questions about the polygraph is: “”. The answer is not clear! It is clear that if you are an intelligence officer and have undergone special training in countering polygraph tests, then a novice polygraph examiner will not “bring you to clean water.” However, if the polygraph examiner also has extensive experience, then deceiving him is not an easy task. One might even say - impossible!
For information: In the staff of AIC "Detector" all polygraph examiners are highly qualified, which is confirmed by their certificates.

In addition to analyzing the content of statements and nonverbal behavior, there is another method for detecting lies, namely recording the physiological reactions of liars. At all times, it was believed that lying is accompanied by the physiological activity of various organs of the body. For example, previously in China, a person suspected of lying was forced to chew rice flour and then spit it out. If the flour remained dry, the person was accused of lying (Kleinmuntz & Szucko, 1984).

A modern method of recording the physiological activity of liars involves the use of a polygraph. The name "polygraph" comes from two Greek words - "poly" (many) and "grapho" (write). This scientific measuring instrument can make an accurate and valid record through an ink recorder on graph paper or an image on a computer display. various types bodily activity (Bull, 1988). The most commonly measured parameters include palm sweating, blood pressure, and respiration (Ben-Shakhar & Furedy, 1990). When conducting scientific research electrical activity of the brain (evoked potentials) is also recorded using a polygraph (Allen & Iacono, 1997; Bashore & Rapp, 1993; Farwell & Donchin, 1991; Johnson & Rosenfeld, 1991; Rosenfeld, Reinhart, Bhatt, Ellwanger, Gora, Sekera & Sweet, 1998). However, the practice of recording electrical activity of the brain within the framework of applied tasks has not yet become widespread. The polygraph is able to accurately record changes in palm sweating, blood pressure and respiration, and is sensitive to even the slightest changes. The device makes recordings by amplifying signals coming from sensors that are attached to different parts of the body. In typical polygraph testing cases, four probes are used. To record changes in the depth and frequency of breathing per area chest Pneumatic tubes are placed in the stomach and stomach. Changes in blood pressure are recorded using a special cuff that is wrapped around the shoulder, and palm sweating is recorded using metal electrodes attached to the fingers (Ekman, 1992).

So, the polygraph records physiological and changes in its parameters. In this case, changes in indicators are often associated with fluctuations in the level of arousal. It is believed that lying will cause more high level excitement than telling the truth. This may be the result of a feeling of guilt in the subjects or, more likely in the context of polygraph testing, the emergence of fear of detection of a lie.

A polygraph is sometimes called a lie detector, but this term is misleading. The polygraph does not detect lies, but only the arousal that can result from telling a lie. There is no way to detect a lie except indirectly, since the pattern of physiological activity characteristic of telling a lie simply does not exist (Saxe, 1991).

It is not difficult to imagine that such an indirect method of detecting lies may well lead to incorrect judgments, for example, when the level of arousal in liars does not increase or when truth-tellers experience very high arousal. Good example The appearance of strong excitement in a truth teller, even stronger than in a liar, is illustrated by the biblical story of two women, each of whom considered a small child to be her own. Both women appeared before King Solomon, who proposed as a solution conflict situation tear the child in half and divide it between the disputants. One mother agreed with this decision, while the other reacted with confusion. Noticing the increase in arousal in the last woman, King Solomon realized that she was the real mother and gave her the child (Ford, 1995). Another example in which a person experiencing arousal would not necessarily tell a lie is the case of Roger Keith Coleman. He was accused of raping and brutally murdering his half-sister (Ford, 1995). Coleman insisted on his innocence; in addition, the charges against him also included vulnerabilities. For example, after his conviction, four people came forward to say that they had heard another man confess to the crime. Using last chance to prove his innocence, Colman asked for a polygraph test. The test was conducted 12 hours before the scheduled execution. As a result, it was announced that Coleman had failed the test and would be sentenced to death that evening. Perhaps unsurprisingly, Coleman failed the polygraph test. It is difficult to imagine how he could avoid extreme excitement when responding to decisive issues during the test, regardless of whether he was guilty or not. I will return to the problem of erroneous decisions later.

Currently, polygraph tests are used to investigate crimes in all countries of the world, including Canada, Israel, Japan, South Korea, Mexico, Pakistan, as well as the Philippines, Taiwan, Thailand and the USA (Lykken, 1998). However, the use of the polygraph is limited in most countries, with the exception of the United States, where many such tests are performed (Barland, 1988). Polygraph testing in the United States is most often used in criminal investigations and trials, as well as for trustworthiness purposes (Gale, 1988). The Decree on the Use of the Polygraph (issued in 1988) placed restrictions on the use of polygraph tests to screen personnel. Test results are sometimes used as evidence in criminal trials in the United States (Honts & Perry, 1992), although not in all states (Patrick & Iacono, 1991) (see Cohen, 1997, and Faigman, Kaye, Saks and Sanders, 1997, review of past practices and current legal status of polygraph evidence in the United States). However, in many court cases in the United States, evidence based on the use of a polygraph is still not admissible or binding because the test is considered inaccurate. Another reason is that jurors may be impressed by the scientific nature of the evidence (Honts, 1994). However, a recent experimental study by Myers and Arbuthnot (1997) does not support this claim. Dummy jurors (Ohio University College students) were asked to reach a verdict based on a number of pieces of evidence, including forensic evidence (hair samples and fingerprints that were found in the victim's apartment that belonged to the suspect), medical evidence (sperm found at the crime scene that matched the sample suspect's semen), eyewitness testimony (an eyewitness testified that he saw the suspect leave the victim and appear to be hiding something under his jacket), and finally, polygraph evidence (testing showed that the suspect was guilty). The jurors considered last view evidence is classified as least convincing.

Other countries, such as the Netherlands and the UK, do not use polygraph tests. In the UK, after a sensational spy case, the government announced its intention to conduct pilot studies of the effectiveness of polygraph testing. A number of eminent psychologists from Great Britain formed a working group under the leadership of Professor Tony Gale. The team's task was to provide a report on the status of polygraph testing. The results were horrifying. Psychologists questioned the accuracy of the polygraph test results (this issue and a number of other issues that were contained in the psychological report will be discussed in this chapter). Thus, testing procedures have not been standardized to a degree that can be considered satisfactory in psychometric terms. The researchers also encountered difficulties in validating the testing methodology and practice of different polygraph specialists. They ultimately decided that certain aspects of polygraph testing, in particular misleading the subject, were contrary to British law, thereby rendering the test results inadmissible in a British court (report working group British Psychological Society on the use of the polygraph, British Psychological Society, 1986, p. 92). The UK government subsequently abandoned plans to introduce polygraph testing.

In other words, the use of a polygraph is controversial. Proponents and opponents of this method engage in heated, lively debates, challenging each other in the media, in scientific and professional journals and books. In addition to the debate between opponents and defenders, there is also controversy within the polygraph testing community. Two of the leading and perhaps most prominent researchers in the field, David Raskin and David Leekken, have engaged in a protracted debate over the reliability and validity of various polygraph tests. They argue in scientific publications, as experts testifying in court, and as possible opponents in trials against each other. More recently, other specialists have joined the Lykken-Raskin debate, such as Furedi and Iacono (Lykken supporters) and Honts (Ruskin supporter). It is worth recalling once again that both sides are in favor of the use of polygraph tests and that their dispute is related to which test should be used. This chapter gives general idea about the existing scientific literature regarding polygraph tests, and will present arguments on both sides.

I will discuss the polygraph in detail for the following two reasons. First, many people have heard of the polygraph (for example, from the (American) media and movies), but may not know how the tests are performed. Therefore, this chapter may improve the knowledge level of some readers. Secondly, many specialists (including those who work in the judiciary) have a sharply negative attitude towards the polygraph. You can often hear comments like this: “I don’t believe in the polygraph test, it’s completely unreliable.” In my opinion, the negativity of this attitude is somewhat exaggerated. As I will demonstrate in this chapter, under certain conditions, polygraph tests can be used to detect deception. Much attention will be paid to the role of polygraph examiners, as their role is critical, especially in the preparation and administration of the test, as well as in the evaluation of test results. To correctly conduct polygraph tests, qualified specialists are required, and they are faced with a far from easy task.

A polygraph (another name is a lie detector) is used in forensic science to determine the guilt of a suspect. Also, when applying for employment in some companies, job seekers will undergo a polygraph test. Thanks to this, management receives information about whether potential employees have a tendency, for example, to theft, etc.

It should be immediately noted that polygraph testing of people is allowed only to those who have completed special courses and received a certificate of the required type.

Lie detector device

Before agreeing to take a polygraph test, you should inquire about its structure and operating principle. Lie detector - device touch type, which records human physiological indicators using special sensors - blood pressure, heartbeat, muscle tone, blinking frequency, sweating, etc.

The sensors are connected via wires to a computer, on the monitor of which you can see the test results in the form of various graphs.

It should be noted that attempts to “falsify” the survey results have always been made. The question of how to fool a polygraph has been around for as long as the lie detector itself.

What testing looks like

Sensors are attached to the thing being tested on all sides. And in addition, they sit you down on another sensor and ask you to remain motionless. The fact is that reactions to provocative questions even include involuntary muscle contractions.

Before the procedure begins, the subject must inform the examiner if he has any concerns or needs to go to the toilet. Comfortable state of the person being tested - required condition such verification, otherwise the results will be far from objective.

Also, at the beginning of the process, the device reads the initial parameters from the person. This is done because many people are concerned about the fact of verification, and not about hypothetical guilt. An honest and decent person may well turn out to be neurotic or simply overly impressionable. That is why the indicators obtained during the audit must be compared with the initial ones.

Is this test really that serious?

In principle, it is quite possible to fool a lie detector. After all, a polygraph test is carried out by a program based on measurements physical indicators your body: heart rate, respiration, blood pressure, etc. And if you remain calm when answering the questions you are asked, then changes in state will not be perceived by the device.

At first glance, this is the whole secret of how to deceive a polygraph. But know that the program will also take into account your efforts to remain calm and control your own reactions. And, in turn, he will use a “distracting maneuver” - for the first time (about twenty minutes) you will be asked the most simple questions in order to lull vigilance and “adjust” the device specifically for you.

What can affect the result

The main factor is the correct internal state of the subject. How to pass a polygraph according to all the rules? The person being tested must sit completely static; he is prohibited from moving his arms, legs, eyes, head, tensing any muscles, or even swallowing saliva. These actions can cause an involuntary physiological reaction, recorded by a polygraph and affecting the result.

So, is it possible to pass a polygraph test with the result you want? Or, to put it more simply, can the device be fooled?

If a person is accused of a serious crime, then sometimes a lie detector may be the only chance to prove his own innocence. Therefore, it is useful to have an idea of how to pass a polygraph at the Ministry of Internal Affairs.

How it's done

First of all, on the eve of testing, be sure to get a good night's sleep. Answers to polygraph questions should be given as truthfully as possible; in case of any misunderstandings, everything should be explained in detailed detail as calmly as possible.

If your biography contains any violations or other negative aspects, you should not remain silent about them. It is much wiser to immediately openly talk about them. There is no point in being nervous for a law-abiding citizen.

How to pass a polygraph to your advantage

Experts working with the device assure that this is not easy to do. Only a person who has thoroughly studied the principle of its operation and has excellent self-control can outwit a lie detector.

At first glance, maintaining external equanimity is not such a difficult task. But the detector captures and records the parameters of the internal state! And it is very, very difficult to control them. If a person tells a lie in response to a question, his body reacts to the lie involuntarily, regardless of the desire to hide the truth. The device will only be able to “swallow” an obvious lie when the subject either sincerely believes what he is saying, or gives an answer “automatically” - i.e. without analyzing your own words.

Don’t get hung up on the significance of what’s happening and don’t immediately prepare for the worst. To successfully pass the test, you should simply relax, especially if you are not guilty of anything. IN in this case the question of how to pass a polygraph simply should not bother you.

With this approach, your anxiety will subside, you will not begin to painfully go through all your past sins. Let's say they often ask whether there have been episodes of theft in your life. An honest and decent person, who is fundamentally incapable of appropriating someone else’s property, suddenly remembers a trivial childhood episode - a toy taken without permission from kindergarten.

This memory confuses him, internal tension is immediately recorded by the device, and an honest answer “No” will be recorded as a lie. That is why, during testing, do not try to go through past memories and do not delve deeply into the questions asked. Answer honestly, but at the same time slightly “mechanical” and rather indifferent.

How to achieve automation

As already mentioned, a detached, calm state will help to deceive the polygraph - when a person does not try to form mental images in his mind life situations. But it’s not easy enough to completely detach yourself and give negative and positive answers in a timely manner, alternating them correctly. Only a few truly succeed in this.

How to achieve the desired state? Try to mentally switch to any other problem that is relevant to you. In this way, you seem to isolate yourself from the questions being asked; accordingly, you do not analyze them and do not imagine images of situations that are critical for you.

From the history of the lie detector

The first version of the polygraph was invented and used in 1895 by Italian psychiatrist Cesare Lombroso. He called the device a hydrosphygometer.

But a real lie detector capable of assisting in the investigation of crimes appeared only in 1921. It was invented by police officer John Larsen.

The polygraph turned out to be able to record the most insignificant changes in the psychophysical state of the subject, thanks to which the specialist became clear about the degree of truthfulness of his answers. This principle formed the basis for the use of a lie detector for a long time and continues to this day.

For whom testing is contraindicated?

Women who are pregnant have the right to refuse the test. In addition, it is prohibited to test adolescents who have not reached the age of majority. If necessary, they can undergo testing with the written permission of the parents (as well as persons guarding the child) or in their presence.

An important point: passing a polygraph test is possible only with the written consent of the subject - you must know this in order to prevent violation of your rights.

Now you know how to pass a polygraph competently. We hope this information will help you avoid mistakes and defend your own interests if necessary.