Does our speech change when we cannot gesture?

•Previous research has found that speech and gesture are closely related.•It has been found that preventing gesture can influence some aspects of speech.•In this study, an instructional director–matcher task was set up where directors were not able to gesture for half of the experiment.•Contrary to expectations, there was no difference between directors’ speech with and without gesture.

Do people speak differently when they cannot use their hands? Previous studies have suggested that speech becomes less fluent and more monotonous when speakers cannot gesture, but the evidence for this claim remains inconclusive. The present study attempts to find support for this claim in a production experiment in which speakers had to give addressees instructions on how to tie a tie; half of the participants had to perform this task while sitting on their hands. Other factors that influence the ease of communication, such as mutual visibility and previous experience, were also taken into account. No evidence was found for the claim that the inability to gesture affects speech fluency or monotony. An additional perception task showed that people were also not able to hear whether someone gestures or not.