Why do people gesture when they speak?
Yagmur Kisa (UChicago)
On one proposal, people gesture because they speak: Gestures reflect and facilitate speech production processes. Alternatively, people gesture because they think: Gestures reflect non-linguistic thinking processes. We show that (i) there is no evidence that gestures facilitate speech production and (ii) at least some co-speech gestures grow out of thinking processes that are independent of speaking. These results suggest that gestures are not a sub-system of speech production.