How Referential Gestures Align with Speech: Evidence from Monolingual and Bilingual Speakers

When speaking, people often produce gestures that are closely timed with the speech with which they constitute a semantically coherent unit. Analyzing the temporal patterns between the two modalities may reveal insights about how speakers plan them. Using elicited narratives, we tested English/French monolinguals and bilinguals to check whether bilinguals, known to experience a higher degree of competition in lexical access, show a different pattern of gesture-speech alignment compared to that of monolinguals. Results revealed no difference in the temporal patterns between gestures and co-semantic speech for the two language groups. Synchronous gestures were significantly more frequent than asynchronous ones; asynchronous gestures both preceded and followed the correlated speech, yet preceding gestures tended to occur more often. A qualitative analysis conducted for asynchronous gestures revealed that they may serve a rhetoric function. We argue that the variability in gesture-speech timing results from speakers' strategic use of gesture.