A strange thing happens when talking we usually don't notice - our hands move. They draw precise shapes, caress invisible objects, punch the air and quiver. What is the point of all this hand waving?
The popular assumption has generally been that nonverbal behaviour communicates emotion. This idea goes back more than two thousand years to the time of Cicero who thought that each emotion had a particular bearing associated with it (Knapp, 2006). While emotions are certainly part of the mix, modern approaches to nonverbal behaviour have examined all kinds of factors like dominance, intimacy, deception and influence.
Explaining gestures - the movements we make with our hands, arms, body, head or face - has been a particularly controversial area of nonverbal behaviour. Some have argued that gestures communicate vital aspects of meaning while others have argued they play a role in word retrieval.
Gesture as thought
Those who argue gesture is filled with meaning say the evidence is very strong. Supporting research comes from studies where people are asked to tell the story of a cartoon with which they are presented (e.g. Hadar and Pinchas-Zamir, 2004). They are surreptitiously video-recorded narrating the story. This video is then shown to participants with either just video or audio, or both together. These participants are then asked to answer a series of questions about the original story. The results show those who have seen the video along with the audio are better at answering questions about the story.
On top of this, researchers have found people gesture more when they can see the person they are talking to compared with, for example, when they are on the telephone. There is even evidence gestures used while telling a story become encoded into memory such that they affect later retellings of the story.
What some argue from evidence like this is firstly that gestures and speech are too highly connected to be separate channels of communication. Each channel informs the other, and to remove gestures is to remove information. Following on from that, it is argued, people are actually thinking with their hands and so, by watching the hands move you can effectively see people's inner thoughts.
Gesture as memory
Not everyone is so sure this type of evidence is really that strong. While it would be foolish to argue gestures have no communicative function, some argue the case has been overstated. Instead, perhaps gestures do aid communication but by helping us form our own speech rather than with the communicative properties they have in themselves.
This theory has the great advantage that it's relatively easy to test. Simply tie someone's hands behind their back, then see how it affects their talk. Indeed, this is what has been done in experimentally controlled conditions and there is some support that people's talk does become less fluent when they're not allowed to gesture. In addition to these, studies on the 'tip of the tongue' phenomenon have shown that people unable to gesture find it harder to retrieve the right word.
Other evidence comes from brain damaged patients suffering from aphasia - a partial or total loss of the ability to speak. Aphasics have been shown to gesture much more when unable to retrieve a particular word.
What are gestures for?
Intuitively it seems likely gestures have some sort of function - they aren't just for exercising our arms and hands. For psychologists, working out their exact function has long surpassed Cicero's ideas about the communication of emotion. Perhaps gestures contain meaning, displaying the mind at work or perhaps they help us produce speech more effectively. Either way gestures are not just useless by-products of some other process, but provide vital support for our communicative abilities.
» This post is part of a series on nonverbal behaviour.
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