Speaker-gaze Modulates the Inter-personal Repetition of Hand Gestures

One study found that observers retained more information from hand gestures that speakers gazed at, possibly because speaker-gaze shifted observers' attention covertly. Speaker-gaze may thus modulate the role of gestures in communication. One hypothesized communicative function of gestures, and specifically of the inter-personal repetition of gestures, is to facilitate the process of creating common ground (grounding). Therefore, speaker-gaze may also influence the inter-personal repetition of gestures. In an experimental study, we found that participants were more likely to repeat another speaker's gestures if the original speaker gazed at the gestures. Moreover, speaker-gaze was a better predictor of this repetition than participants' own gaze. This supports the hypothesis that speakers' gaze at their gestures leads to covert attention shifts in observers, causing the gestures to be processed differently. Speaker-gaze could therefore be a valuable cue to the processing and production of gestures by artificial systems that interact with humans.