A review of the polygraph: history, methodology and current status

The history of research into psychophysiological measurements as an aid to detecting lying, widely known as the ‘lie detector’ or polygraph is the focus of this review. The physiological measurements used are detailed and the debates that exist in regards to its role in the investigative process are introduced. Attention is given to the main polygraph testing methods, namely the Comparative Question Test and the Concealed Information Test. Discussion of these two central methods, their uses and problems forms the basis of the review. Recommendations for future research are made specifically in regards to improving current polygraph technology and exploring the role of the polygraph in combination with other deception detection techniques

A Comprehensive Meta-Analysis of the Comparison Question Polygraph Test

We conducted a meta‐analysis on the most commonly used forensic polygraph test, the Comparison Question Test. We captured as many studies as possible by using broad inclusion criteria. Data and potential moderators were coded from 138 datasets. The meta‐analytic effect size including inconclusive outcomes was 0.69 [0.66, 0.79]. We found significant moderator effects. Notably, level of motivation had a positive linear relationship with our outcome measures. Information Gain analysis of CQT outcomes representing the median accuracy showed a significant information increase over interpersonal deception detection across almost the complete range of base rates. Our results suggest that the CQT can be accurate, that experimental studies are generalizable, and no publication bias was detected. We discussed the limitations of the field research literature and problems within polygraph profession that lower field accuracy. We suggest some possible solutions