Effects of feedback on self-assessed and actual abilities to tell lies

The present study examined how feedback on lie-telling affects the illusion of transparency which causes liars to assume that their lies are more easily detected than they actually were. To this end, 75 undergraduate students were asked to self-assess their abilities to detect lies and truths in others, and to tell lies and truths convincingly themselves. It emerged that participants scored their lie-telling ability lower than their other abilities. The abilities were tested in a lie-telling task in which participants received false feedback about the detection of their lies. When the feedback implied that they had avoided detection (confirming feedback), participants' self-assessment of their lie-telling capacity increased. When the feedback suggested that their lies had been detected (challenging feedback), self-assessed lie-telling and truth-telling abilities declined. Liars were more often detected after receiving challenging feedback than before receiving it. Feedback effects on actual detection of lies were not observed for the confirming feedback condition. Practical implications of the present results in criminal interrogation and in the courts are discussed.