The Polygraph - Detecting Lies and Finding Truth

Since almost the beginning of time man has sought to verify the truth and detect deception. The polygraph is widely accepted in many countries as the only reliable and validated means to discover lies and uncover the truth.

The UK has not traditionally embraced the polygraph with the same enthusiasm as the USA and Canada. However, recent changes in social perceptions coupled with a refusal to “just accept” a persons word have led to a steadily growing interest in polygraph.

In this article we cover valuable information regarding the polygraph that any person considering taking a test should be aware of.

Bruce Burgess and Guy Heseltine of polygraph examiners Distress Services report.

What is a polygraph?

The polygraph works by tracing changes in a person’s ‘Physiological Conditioning’ during questioning.

This is done by attaching four components to the subject.

• Pnuemograph
  Two rubber pnuemograph tubes are placed around the subject’s upper chest and abdomen. These record breathing and movement.
• G.S.R.
  The GSR or galvanic skin response is measured by placing two finger plates across the ring and index finger of the right hand. These trace changes to your skin resistance during the examination.
• Cardiosphygmograph
  Similar to the pressure cuff your doctor uses to take your blood pressure, the cardiosphygmograph traces changes to your relative blood pressure and pulse rate.

Once the questions have been asked the examiner will read the generated charts to assess truth or deception.

A properly administered test by a fully trained and qualified examiner is highly reliable.

What is involved in taking a polygraph examination?

A polygraph examination usually takes between 2-3 hours beginning to end and consists of three different phases - pre-test interview, collection of charts and analysis of charts.

• Pre-test interview
  During the pre test interview the examiner will explain how the polygraph works, discuss the issue, develop and review all questions to be asked on the polygraph test. This stage is normally the longest to complete and will take anywhere between 45-90 mins.
• Collection of Charts
  During this phase the subject will be attached to the polygraph. The question set which was developed during the pre-test interview will be asked 3 or 4 times.
• Analysis of Charts
  Once the examiner has collected the charts he will analyise the results before giving a decision as to the subject’s truthfulness or deception.

The specialised nature of polygraph means that only a few companies exist in the UK which can offer this service.

Questions to ask a polygraph examiner

There is no official UK regulatory body to oversee the quality and accuracy of an individuals work. It is therefore important that you establish the professional competence of the examiner. Here are some questions you should ask before you undertake a test.

• Is the examiner professionally trained at a polygraph school accredited by the American Polygraph Association? Ask to see certificates. If the examiner does not have certificates he is not qualified!
• Has the examiner undertaken ‘continuous professional development’ training? Remember being trained 20 years ago was fine 20 years ago, however techniques and instruments have changed!
• Does the examiner use up to date computerized instruments?
• Is the examiner part of an established business or is he working out of a suitcase? Is he reluctant to give you a business address - why?
• What quality control procedure does the examiner use? Who is checking the quality of the work? How often is this done?
• Is the examiner a continuing member of the American Polygraph Association? The APA is the industry recognized professional body. If the examiner is not a member, why is this?

Bruce Burgess and Guy Heseltine from Distress Services, have been offering polygraph tests in the UK since 1999.

Links:
Bruce Burgess, Distress Services, Surrey
Guy Heseltine, Distress Services, Norfolk