Is the Inference Rule of the "Control Question Polygraph Technique" Plausible?

Abstract

Two experiments were designed to examine if the inference rule suggested for the controversial control question technique (CQT) makes sense. In Experiment 1 a story of a hypothetical theft was presented to 20 police interrogators. Half of the participants received a story about a guilty suspect and the other half a similar story that described an innocent suspect. Interrogators were asked to evaluate the concern that this person would feel when various questions were presented to him in a polygraph test. Results supported the reasoning of the inference rule proposed for the CQT. Experiment 2 extended the plausibility question to predictions about the relative frequencies of truthful and deceptive outcomes. Opponents of the CQT argued that many innocent examinees would show larger physiological responses to relevant than to control questions and thus yield deceptive outcomes. Analysis of a random sample of actual polygraph tests showed, that truthful outcomes are more common than predicted. It was suggested that some critical views of the CQT tended to overestimate the CQT false positive error rate.

Keywords:

• Polygraph
• Control Question Technique
• Detection Of Deception