Bio – Biological, Feedback – Responses, Poly – Many or more than one, Graph – Recordings/writings. Biofeedback Polygraph.
Also known as BFP, biofeedback polygraph is one of the oldest forms of psychophysiological detection of deception (PDD) technique. During a test, continuous measurements of blood volume pulse, electrodermal activity and respiration rates are taken. These physiological responses to certain types of questions are compared. If the subject is displaying signs of the fight or flight response, they are generally considered to be lying.
Short History
John Larson, a Canadian born U.S. citizen is accredited with the invention of the polygraph machine (1921). He did so at the mere age of 21 whilst studying at the University of California. He combined the previous work of William Marston on systolic blood pressure with new measurements of pulse rate & respiration rate. His protege Leonarde Keeler later added the measurement of skin conductivity and made the device portable. Computerisation of this system gave birth to the modern day polygraph machine.
Polygraph testing has had a tumultuous history with arguments regarding it’s effectiveness and acceptability in a court of law. There are numerous scientific studies either advocating or opposing the probability of a biofeedback polygraph test in different settings. Despite differing probability percentages of articles, a polygraph tests yields results far above that of chance. Legal acceptability differs on a country by country and even state by state basis. In South Africa, there are legal precedents that allow any PDD examination into a court of law on the grounds of corroborating evidence. You can find a short explanation related to CCMA cases and admissibility for South Africa here as well.
Why use it?
Companies are increasingly using biofeedback polygraph testing as a means of screening employees both before and during their employment worldwide and especially in South Africa. This not only reduces risk of employing a bad apple but also negates the possibility of such an individual corrupting your existing staff. The Lie Detection Institute has also successfully identified suspects from major incidents of theft and corruption for multiple firms by means of polygraph testing. Feel free to utilise our testing services or perhaps even train your own internal biofeedback polygraph examiners to bolster your business security.
