Does Sitting on Your Hands Make You Bite Your Tongue? The Effects of Gesture Prohibition on Speech During Motor Descriptions

Several theories of gesture production predict that speech production is affected when gestures are prohibited. The present study sought evidence for these predictions by asking participants to describe how to complete three motor tasks. Half of the participants were prohibited from gesturing during their descriptions. We found that participants who were free to gesture described a higher percentage of key events with semantically rich verbs (e.g., cross, fold) than participants who were not free to gesture. Participants who were free to gesture were also less likely to begin their sentences with the word “and” than participants who were not free to gesture. There were no effects found for other measures of the amount and content of speech produced. Thus, the effects of gesture prohibition on speech production are compatible with the idea that gesturing helps speakers package their thoughts into planning units for speaking.