The way apes communicate may hold clues to the origin of language in humans. Apes gesture with hands and limbs, a way our early ancestors may have communicated before language evolved. A region of the brain called Broca’s area controls the ability to speak in humans. Chimpanzees have a similar area in the brain that controls gesturing. Scientists at the Yerkes National Primate Research Center at Emory University studied communication in groups of chimpanzees and bonobos. The study showed that both groups used 18 facial/vocal displays in similar ways. The study identified 31 gestures in the two groups, however the gestures varied enormously. The meaning of a gesture could change depending on the situation. The study supports the idea that human language evolution began with gestures and not vocalizations.
Have students view the Snapshot and read the synopsis. Use the following questions to guide a class discussion.
- Which part of the human brain controls the ability to speak?
- What function does a similar region in the brain control in apes?
- In apes, which is the more powerful means of communication: vocalizations or gestures? Why?
- In humans, which is the more powerful means of communication: vocalizations or gestures? Why do you think that?
- Do you agree with the hypothesis that, for our early ancestors, gesturing eventually led to complex human language? Why or why not?