Validity and reliability of detection of deception

This project was designed to provide information on the usefulness of polygraph techniques in detecting truth and deception in criminal investigations. The report describes the methodology of each of the eight experiments and studies conducted. In addition to studies involving criminal suspects in a field situation, other studies involved laboratory experiments with a mock-crime paradigm. The lab experiments investigated aspects of the general problems of accuracy and reliability not easily studied in the field situation. They also assessed the usefulness of a number of physiological measures that had received little attention in previous scientific research. Studies also were undertaken to evaluate the commonly-held belief that psychopaths can beat the polygraph, the adequacy of current practices used by field polygraphists, the usefulness of different question structures in polygraph examinations, and the risks of different types of errors in field applications. The project results indicate that polygraph examinations using control-question or guilty-knowledge tests are highly accurate.