The Verifiability Approach: A Meta-Analysis of Published Studies and a Test of a Decline Effect

Abstract

Liars are caught in a paradox: they want to provide details to be credible but not so many they could be discovered being untruthful. The verifiability approach assumes that liars include fewer verifiable details, more unverifiable details (or a similar amount), and a lower proportion of verifiable details than truth-tellers. This meta-analysis included 17 published studies, resulting in an overall medium veracity effect for the number (gu = 0.64, gu = 0.55 without outlier) and the proportion of verifiable details (gu = 0.66). No veracity effect was found for the unverifiable details. The type of lie, the use of an information protocol, and the type of statement moderated the veracity effect on the verifiability approach. No effect was found for motivation. A decline effect only appeared for the number of verifiable details. Recommendations for future studies and field applications are discussed.