Actions Speak Louder in Words

By Mary Beckman
ScienceNOW Daily News
21 July 2006

If you've ever tried to speak to someone who doesn't share your native tongue, you could probably intuit a bit of what they were saying just by how they said it. Anger, happiness, and even confusion traverse the language barrier quite well. Now a new study shows that emotions aren't the only information that piggybacks on our speech: We subconsciously convey important details about the objects around us just by verbally describing them.

Language is largely symbolic--most of the time we use our words to convey ideas. But how we say something can be as important as what we say: "Hey man, nice car!" spoken with enthusiasm carries a much different connotation than when spoken with sarcasm. But can we communicate other information with our speech patterns, such as where the car is or where it's going?

To find out, psychologist Howard Nusbaum and colleagues at the University of Chicago asked 24 college students to describe a dot moving across a screen. The students were told to use one of two sentences: "It is going up" or "It is going down." The team found that when students described the dots going up, the pitch of their voice was, on average, 6 hertz higher than that of those describing the dot going down. The same thing happened when another 24 students read the sentences from a computer screen, indicating people change the sound of their voice according to directional information contained within words. In another experiment, the researchers changed the speed of the dots; they found that, when describing the dots, the students spoke faster when the dots moved faster.

But do listeners pick up on these verbal cues? The team tested this by having volunteers listen to recordings of the students who participated in the dot speed experiment. The volunteers accurately predicted whether the dot was moving fast or slow 63% of the time, indicating they were gathering information about the dots' velocity from the speed at which the sentence was spoken. Changing the speed or pitch of a word may be analogous to hand gestures (holding your hand at hip's height to indicate how tall a kid is, for example), says Nusbaum, who refers to the voice modulation as "spoken gestures." The team reports its results in the August issue of the Journal of Memory and Language.

Scientists have overlooked spoken gestures, says cognitive psychologist Rolf Zwaan of Florida State University in Tallahassee. They are important, he says, because "even if I didn't speak the language, I could pick up something about what's going on based on how the words are spoken." Psychologist Art Glenberg of the University of Wisconsin, Madison, adds that the finding "relates human communication to other neural systems that we know other animals use." For example, one monkey screech indicates an eagle attacking from above, and another screech a snake from below.