Gesturing the solution of a problem-solving task can speed up subsequent performance

The way people gesture impacts problem-solving performance. Particularly gestures that are incompatible with the actions required for subsequent problem-solving slow down problem-solving performance (i.e. interference effect). We investigated whether this interference effect holds if the task allows for only one type of movement (left-to-right movement) instead of a mixture of movement types. Additionally, we studied whether gestures compatible with the actions required for problem-solving facilitate subsequent problem-solving performance. Participants solved a Tower of Hanoi (TOH), then explained the problem-solution with gestures or did not explain the problem-solution, and solved the TOH again. During the second TOH, half of the participants solved the TOH in the same direction (left-to-right), the other half in the opposite direction (right-to-left). Results showed that compatible gestures resulted in faster problem-solving (facilitation effect) but incompatible gestures did not slow down performance (no interference effect). Our study shows that gesturing supports but does not interfere with problem-solving.