Scientific review of psychophysiological detection of deceit

Abstract

Psychophysiological detection of deceit has been in the centre of attention in the recent decade, which correlates with heightened security challenges of a modern world. The article provides scientific discussion about polygraph that is used in criminal investigation. Two most employed polygraph techniques are critically presented, examined and compared: the Comparison Question Test (CQT) and the Concealed Information Test (CIT). Theoretical foundations, objectivity and standardization of testing procedures, ethical and practical issues are analysed. Proponents of the Comparison Question Test have not been successful in their efforts to resolve fundamental problems and limitations with which the technique is challenged. It remains unstandardized and unscientific, separated from science and mainly without attempts to escape from the dead-end. The most influential theoretical backgrounds of CQT technique are examined; however, none of them represents a satisfactory scientific foundation of the technique. Without being scientifically grounded in a verifiable theory, it remains controversial and caught into self-sufficiency, mostly supported by methodologically questionable research findings gained by proponents. To the contrary, the Concealed Information Test is associated with fast development, particularly in the field of neurology, and is considered to be less disputed and to be partly supported by a sound scientific ground. Applying the Concealed Question Test, somewhat naïve and disputable detection of lies typical of the Comparison Question Test is replaced by a search for information that lies concealed in the suspects’ memory. However, the Concealed Information Test also has been challenged by serious deficiencies, which bring forward a question about justification of the use of the polygraph.

Keywords

• polygraph
• Comparison Question Test (CQT)
• Concealed Information Test (CIT)
• deceit
• objectivity