All mouth and trousers? Use of the Devil’s Advocate questioning protocol to determine authenticity of opinions about protester actions

Abstract

We examined the Devil’s Advocate lie detection method which is aimed at detecting lying about opinions. In this approach, participants give reasons for why they hold an opinion in the eliciting-opinion question and counter-arguments to their opinion in a devil’s advocate question. Truth tellers (n = 55) reported their true opinion about protestor actions, whereas lie tellers (n = 55) reported the opposite of their true opinion. Answers were coded for number of arguments and plausibility, immediacy, clarity and scriptedness. Data were analysed with analyses of variance with veracity being the sole factor. Supporting the hypothesis, truth tellers provided more pro-arguments than lie tellers and to all eliciting-opinion questions their answers sounded more plausible, immediate and clear than lie tellers’ answers. The opposite pattern was predicted for the devil’s advocate question but not found, likely caused by the simplification of the question. Neither was being scripted a diagnostic veracity indicator.