Chimps Cheer for Attention

March 15, 2007 — Chimpanzees will do almost anything to capture the attention of a person with a banana, including using Bronx cheers (otherwise known as raspberries), according to new research.

The chimp sounds might not be pretty, but they are evidence that at least one nonhuman primate species can invent new sounds, or give novel meaning to existing ones, a trait believed to play a role in language evolution.

In the case of chimpanzees, sheer frustration seems to drive their ability to communicate with people.

"If a human (holding a banana) is turned away or oriented away from the chimp, it might try a raspberry or extended food grunt to get the person's attention," lead author William Hopkins explained to Discovery News.

"If the human does not respond, the chimpanzee might try making some sound again, or it might try another attention-getting behavior," added Hopkins, who is a research associate at Yerkes National Primate Research Center and an associate psychology professor at Berry College.

He also said that if the person with the coveted banana is turned toward a chimp, the chimp might try another visual signal, such as pouting with its lips, or it might even offer some leftover food, or another object in its enclosure, to exchange for the fruit.

For the study, recently published in the journal Animal Behavior, Hopkins and his team videotaped how chimps reacted under such circumstances.

Nearly all of the attention-getting calls recorded were in response to a human holding a banana. The apes rarely called when just the banana was in front of them, and they only produced attention-getting sounds sporadically when the person stood in front of them with no banana.

Since only some chimp populations appear to have such attention-getting vocal skills, Hopkins thinks "chimps that are socially smart have figured out how to use these sounds."

Kim Bard, a researcher in the Center for the Study of Emotion at the University of Portsmouth, conducted a number of chimp communication experiments at Yerkes in the 80's and 90's.

Bard told Discovery News the conclusion that chimps "share with humans a generative capacity for communication" fits with her experience..

"I have heard the raspberry, or sputter, vocalization quite a lot at Yerkes and other chimpanzee facilities, and it can be quite loud and attention-getting," she added.

Charles Menzel, a research associate in the George State University Language Research Center, added, "The capacity of chimpanzees for interactive communication has often been underestimated and definitely merits additional study."