Lying and commitment: The case of pointing gestures

In this paper, we examine pointing gestures that accompany underinformative definite articles and pronouns in German. Ongoing discussions on the definition of lying reveal a contrast between traditional, narrow definitions that focus on what is said and more recent definitions that emphasize commitment. Through two experiments, we demonstrate that first, deceptive pointing gestures are judged as lies to the same degree as speech only. This finding can be interpreted as support for a commitment-based definition of lying, or be explained by assuming that the pointing gestures in our experiment are part of the assertion. Furthermore, our results show that speakers are perceived to be committed to the content of their pointing gestures, although in comparison to speech only, ratings on commitment were lower. However, none of the two commitment-related properties, accountability and restricted deniability, accurately predicts the similarity between pointing gestures and speech for lie ratings. In conclusion, our findings present empirical challenges to both traditional and commitment-based definitions of lying.