Gestures Convey Message: Learning in Progress

Previous studies showed only that students who spontaneously gesture learn better, leaving uncertain whether gestures simply reflect an emergent understanding or help create it. The finding that even concocted gestures improve scores "allows us to make the scientific argument that gesturing is causing an improvement in learning," Cook said.

In effect, she concluded in a report last year with the University of Chicago's Susan Goldin-Meadow, "Children may be able to use their hands to change their minds."

How gestures help consolidate new information remains a mystery. One idea is that gestures help a listener focus on what is being said. But experiments by McNeil -- in which a teacher makes gestures that don't match what is being said -- suggest that gestures have effects on their own, independent of speech.

Another possibility is that gestures lighten the cognitive load during problem solving, leaving more mental power for memory. In one study, people were asked to memorize a list of words and also explain a math problem. Those who were allowed to gesture while explaining the math did better on the memorization than those who were told not to move their hands.

Gesture and speech may also work best on different kinds of information.

"The meaning of speech is clear, but in some cases it may be too precise," Cook said. "Gestures may be better at conveying broader concepts."

So what about those Italians?

As it turns out, they probably don't deserve their reputation for gesturing more.

"The biggest difference between cultures seems to be the size and space you're allowed to take up with your gestures," Cook said.

Italians, she said, simply "gesture larger."