Gestures can help change ones thoughts
For the study, a team at Chicago University recruited volunteers to solve a problem known as the Tower of Hanoi. It is a game in which one has to move stacked disks from one peg to another.
After they finished, the volunteers were taken into another room and asked to explain how they did it. Then they tried the task again. But there was a trick: For some people, the weight of the disks had secretly changed, such that the smallest disk, which used to be light enough to move with one hand, now needed two hands.
The subjects who had used one hand in their gestures when talking about moving the small disk were in trouble when that disk got heavier. They took longer to complete the task than did people who used two hands in their gestures – and the more one – handed gestures they used, the longer they took.
This shows that how one gesture affects how one thinks; researchers suggest that the volunteers had cemented how to solve the puzzle in their heads by gesturing about it (and were thrown off by the invisible change in the game).
In another version of the experiment, the volunteers were not asked to explain their solution; instead, they solved the puzzle a second time before the disk weights were changed.
But moving the disks didn`t affect performance in the way that gesturing about the disks did. Those who gestured did worse after the disk weights switched, but those who moved the disks did not, they did just as well as before.
"Gesture is a special case of action. You might think it would have less effect because it does not have a direct impact on the world, as gesturing about an act requires you to represent that act," lead author Susan Goldin Meadow said.