Most frequent questions

Professional polygraph examinations and lie detection testing / Most frequent questions /

What is a polygraph?

The term "polygraph" translates to "many writings." The name refers to the manner in which selected physiological activities are simultaneously recorded. The polygraph measures predictable changes in a person's body that are associated with the stress of deception. These changes include alterations in heart rate, breathing, and electrodermal activity (emotional sweating). Many other changes occur as well: the pupils get larger, digestion slows, the body's blood supply is redistributed away from the skin and gastrointestinal regions and toward the muscles, etc. The measures used by the polygraph were found early on to be simple to record, they were sensitive (even minor changes in stress levels caused physiological changes to occur), and they are accurate.

What does a polygraph examination consist of?

A polygraph instrument will collect physiological data from at least five systems in the human body. Typically, convoluted rubber tubes that are placed over the examinee's chest and abdominal area will record thoracic activity. Two small pads are attached to the fingers or palm that will record changes in skin sensitivity caused by a light sweating of the hands, and a blood pressure cuff will record cardiovascular activity. And so on.

A typical polygraph examination will include a period referred to as a pre-test, physiological monitoring phase and an analysis phase.

In the pre-test, the polygraph examiner will complete required paperwork and talk with the examinee about the testing process and the information surrounding the issue(s) to be resolved. During this period, the examiner will discuss the questions to be asked and familiarize the examinee with the testing procedure.

During the chart physiological monitoring phase, the examiner will administer and collect several polygraph charts for analysis. Following this, the examiner will analyze the charts and render an opinion as to the truthfulness of the person undergoing the examination.

The examiner will offer the examinee an opportunity to explain physiological responses in relation to one or more questions asked during the examination.

Are there errors in polygraph examinations?
(False Positive, False Negative)

Today, polygraph testing remains the most accurate means of developing and verifying the truth and detecting deception. The tests reveal the accuracy is an amazing 98%. While the polygraph technique is highly accurate, errors can occur. Errors may be caused by the examiner's failure to properly prepare the examinee for the examination, or by a misreading of the physiological data on the charts obtained. The single-issue (one question) polygraph exam, conducted properly by a qualified examiner, is most accurate. Accuracy of the multi-question exam drops to around 90 percent due to a number of psychological factors. These statistics do not include "inconclusive" results in which no opinion can be made from the polygraph charts, which happens about 20% of the time.

Errors are usually referred to as either false positives or false negatives. A false positive occurs when a truthful examinee is reported as being deceptive; a false negative when a deceptive examinee is reported as truthful. Research indicates that false negatives occur more frequently than false positives; however, other research studies show the opposite conclusion.

Since any error is damaging, examiners utilize a variety of procedures to identify the presence of factors which may cause false responses, and to insure an unbiased review of the polygraph records:

Protective Procedures:

• an assessment of the examinee's emotional state
• medical information about the examinee's physical condition
• specialized tests to identify the overly responsive examinee and to calm the overly nervous
• control questions to evaluate the examinee's response capabilities
• factual analysis of the case information
• a pre-test interview and detailed review of the questions
• quality control reviews

Examinee's Remedies
If an examinee believes that an error has occurred, there are several remedies available to include the following:

• request a second examination
• retain an independent examiner for a second opinion
• file a complaint with a state licensing board

Who should take a polygraph test?

Any person who desires to verify their truthfulness regarding a specific situation or incident. Any person who intends to lie or withhold any relevant information about the issue under consideration should avoid the process.

What are "countermeasures"?

The unauthorized and undisclosed use of drugs, alcohol, subtle movements, self induced pain or conflict and mental gymnastics are all considered countermeasures. Countermeasures do not help an examinee taking a polygraph change the final result. Instead, competent well-trained polygraph examiners are trained to look for the tell tale indicators of attempts to alter the appearance normal physiological activity in the body, which makes for a conclusive finding of deception.

How old does someone have to be?

Depending upon the mental age, subjects over the age of 14 can be examined. The examiner must first have written consent of a parent or guardian.

Will a medical condition affect the examination?

A polygraph exam does not cause any direct injury to the person being tested. The only discomfort is a standard blood pressure cuff which goes on the arm and is typically inflated for less than six minutes at a time. There are increased stress levels during the testing process, which should be considered. Some medical conditions are sensitive to increased stress levels, such as some heart conditions. Depending on the medical condition, an approval from the treating physician prior to conducting an exam on someone may be recommended.

Can a pregnant woman undergo a polygraph examination?

Pregnancy does not affect the outcome of a polygraph exam unless the fetus is making excessive movements or causing pain to the mother. As a standard practice, for liability and some other reasons only, we do not examine a pregnant woman.

Does a person's high blood pressure affect the polygraph test?

Not usually. While blood pressure is one of the physiological reactions measured, it does not affect the accuracy of the test.

Will drugs or alcohol affect the accuracy of a polygraph test?

The use of drugs and/or alcohol will not assist someone to beat a polygraph test. Polygraph examiners utilize certain procedures during the examination to ensure that each person undergoing an examination is responding naturally throughout the testing procedure. If you are taking any medication you need to inform the polygraph examiner prior to beginning the test. Physiological affects that drugs have on people are immediately seen in polygraph chart tracings. Irregular physiological recordings must be satisfactorily explained.

What affect does being nervous have on the exam?

Everyone who submits to a polygraph is nervous but for many different reasons. The polygraph instrument measures changes in a person's physiology during the course of the test. Nervousness is a generalized condition which exists throughout the entire exam, not just on one or two questions. Because nervousness exists during the entire test process, it will not affect the test score. Extreme nervousness, however, may cause a person to fidget or not sit still during the exam, and this could distort the test enough so that the results can not be analyzed. In general, though, being nervous will not change a person's test results. Most people are nervous when doing anything new for the first time.

Innocent:
Although most truthful persons believe they should pass a polygraph test, they are often worried that something might go wrong. This doubt will cause the person taking the test to experience a heightened sense of anxiety about the test itself. This kind of nervousness is normal and has no effect on the positive outcome.

Guilty:
Guilty persons are nervous also, but for a very different reason. The guilty tend to be afraid they are about to be exposed. When a guilty person's bad actions are exposed, that guilty person will frequently suffer some negative consequence as a result of having done a bad thing. Being nervous about being exposed or about being punished for having done something wrong is also normal but it tends to help expose the guilty and deceptive.

How long does a polygraph examination take?

A professionally administered polygraph examination should normally take around 3 hours to properly administer from start to finish. A professional examiner will go through several structured test phases to ensure that it will work accurately. During the different phases the examiner and the person taking the test will become very involved in discussing the details of the test and the manner in which the questions are presented. Examinees often feel the need to fully explain their circumstances during the pretest. This is not discouraged by the examiner. The examiner will also attempt to answer each question presented to them by the examinee.

What questions will be asked of me during a polygraph exam?

Each and every question to be asked a person undergoing an examination is discussed in detail with that person in the pretest phase prior to the physiological monitoring portion where test charts are obtained. No professional polygraph examiner will ask a surprise or trick question during the monitoring phase. It is not only unethical for an examiner to ask a surprise question but responses to these types of questions do not accurately indicate truthful/non-truthful results.

Test Questions:

• Are limited to "Yes" or "No" answers
• Must have definitive objective answers and may not be opinions
• Must relate to past events of a factual nature
• Wording of questions must only have one interpretation
• In the same exam must be related to one another. If distinctly separate issue types must be covered, they must be asked in separate examinations.

How many issues can I be asked about?

The most accurate test which can be conducted is the single issue test. If more issues must be explored, more questions must be asked and another exam must be designed and conducted following the first one. This usually adds to the time and cost involved. An effect called "anti-climax dampening" makes test results less reliable with an increase in the number of relevant test questions. A healthy individual can only produce readable polygraph charts for a limited period of time. After this time has expired, it is not possible to generate a conclusive polygraph test and any further testing must be scheduled for a different day.

Why does the examination cost so much?

Polygraph examiners are highly trained professionals, all with college degrees, who provide a very specialized service. This service requires the examiner to purchase expensive equipment and pursue continuing education in order to maintain a high degree of proficiency and licensing. The process of asking "just one question" could take hours, due to the diagnostic process involved, so a single exam often takes an examiner an entire working day (including travel). In most cases, the polygraph is performed because there simply is no other reasonable way to get the desired information, such as when there is no evidence one way or the other, or when it is simply a "he-said-she-said" situation. For example, a person might spend thousands of dollars on surveillance, investigation and other investigative means while the same information could be obtained for a fraction of the price with polygraph, resulting in thousands of dollars saved. The fees charged for polygraph testing are reasonable when considering the cost of training and equipment, degree of specialization and worldwide need for this unusual service.

Is the polygraph exam confidential?

Yes. The examiner works for and reports directly to you, the client. The examiner must decline any exams when a known conflict of interest exists. Admissions of criminal conduct are not revealed to anyone except the client unless authorized under the government law regulations.

Do I get the results of my test?

In each case a polygraph examiner should tell the examinee the results. In cases where examinee has a problem with a question, the examiner should bring that problem question to the attention of the person taking the test so as to give them a specific opportunity to resolve that problem.

Should someone prepare for an examination?

For best results, a person taking a polygraph should be well-rested and free of any extraordinary fatigue or stress factors on the day of the exam. This means getting a good night's rest, eating normally, and avoiding stressful incidents (arguments, interrogations, emergencies) prior to the exam. We suggest postponing the examination until the cause of any physical pain has been remedied, rather than attempting to control the pain with medication. If the examinee is taking regular prescription medications he/she should continue taking those medications as prescribed. If the prescription medications are taken infrequently "as needed" then we generally advise not to take these medications until after the exam. Aspirin or other mild over-the-counter medications should have no affect on the exam.

What should I look for when hiring an examiner?

Make sure the examiner has a current license. The examiner has been "certified." Every examiner must attend a polygraph training certified program. After graduation, the examiner must conduct a certain number of exams during an "internship" period. After the internship, the school reviews the examiner's work and grants the certification if this work was done to standards. After certification, most examiners must complete a certain amount of continuing education or advanced training programs. Be aware of an examiner who's been operating for 25 years but has not undergone regular advanced training. Technology changes and examiners must keep current. Look for professional affiliations and membership, such as the polygraph associations or other similar groups which set professional standards for examiners. Make sure the examiner has experience with the type of exam you need.