Home runs and humbugs: Comment on Bond and DePaulo (2008)

Abstract

In 2006, C. F. Bond Jr. and B. M. DePaulo provided a meta-analysis of means and concluded that average lie detection accuracy was significantly greater than chance for most people. Now, they have presented an analysis of standard deviations (C. F. Bond Jr. & B. M. DePaulo, 2008), claiming that there are no reliable individual differences in lie detection accuracy; such differences are due to chance alone. Their conclusions are based principally on studies with college students as lie detectors and lie scenarios of dubious ecological validity. When motivated professional groups have been shown either high stakes lie scenarios or scenarios involving appropriate liars and truth-tellers, average accuracies significantly above chance have been found for 7 different professional groups reported by 12 researchers in 3 countries. The replicated and predicted performance of extremely accurate individual lie detectors ("truth wizards") also undermines the claim of no individual differences in lie detection accuracy. Psychometrically, the stochastic model used is problematic because it does not meet the assumptions of classical test theory.