Vocal and verbal indicators of deception as a function of Lie complexity

The aim of the present experiment was to explain contradictory findings in the relationship between speech disturbances and deception. We hypothesized that lie complexity would have an impact on the occurrence of speech distu rbances during deception. We expected liars to use fewer speech disturbance s (compared to truth tellers) when the lie is easy but to make more speech disturbances when the lie requires a lot of mental effort. We further hypot hesized that truth tellers would include more details in their recall and w ould raise more doubts about their own memory than liars. Forty participants were shown a video and were requested to lie about some aspects of the video and tell the truth about other aspects of the video. O ne lie (giving an inaccurate description of the appearance of one of the pe ople in the video) was easy to fabricate, another lie (making up a reason w hy the person in the video wanted to buy satellite television) was difficul t to fabricate. The results generally supported the hypotheses.