Great Apes and Language: Very Close to Talking Like Us [VIDEOS]

It's no secret that compared to other animals, great apes are leaps and bounds ahead in terms of language development. The complex and varied call dialects chimpanzees exhibit, alongside the impressive sign language abilities of gorillas has shown us as much. But how close are they to developing a verbal language like ours? A new study of Koko the gorilla has found that great apes are closer than ever imagined.

"Decades ago, in the 1930s and '40s, a couple of husband-and-wife teams of psychologists tried to raise chimpanzees as much as possible like human children and teach them to speak. Their efforts were deemed a total failure," Marcus Perlman, a researcher with the University of Wisconsin-Madison, recently explained. "Since then, there is an idea that apes are not able to voluntarily control their vocalizations or even their breathing."

Instead, as the thinking went, great apes must be limited to the purposeful single-context vocalizations that most animals make use of, such as greeting and warning calls.

"This idea says there's nothing that apes can do that is remotely similar to speech," Perlman said. "And, therefore, speech essentially evolved -- completely new -- along the human line since our last common ancestor with chimpanzees."

However researchers are now finding new evidence that they may have jumped the gun on that assumption. (Scroll to read on...)

For instance, a study recently published in the journal PeerJ details how bonobos, the great ape species sometimes called "pigmy chimpanzees," are actually capable of protophone babbling - something that was long thought only achievable by human newborns. More about that here.

The conclusion was then that bonobos are the exception to the rule - potentially a consequence of the fact that, among all living mammals, they boast the most genetic similarities with humanity.

Now however, Perlman has determined that gorillas too are far more linguistically advanced than experts had thought, and might even be on a language evolution fast-track (respectively) similar to that of bonobos and humans.

Five years ago, Perlman started looking for clues about language evolution at The Gorilla Foundation. It is here that Koko the gorilla has spent more than 40 years living a life full of human interaction while working with psychologist Penny Patterson and biologist Ron Cohn. (Scroll to read on...)

[Credit: The Gorilla Foundation via Animal Cognition ]

"I went there with the idea of studying Koko's gestures, but as I got into watching videos of her, I saw her performing all these amazing vocal behaviors," Perlman explained.

The researcher wound up sifting through 71 hours of video of Koko interacting with Patterson and Cohn. As a result, he found repeated examples of Koko performing nine different, voluntary behaviors that required control over her vocalization and breathing. These were learned behaviors that were associated with a effort to bridge the fundamental gap between human and gorilla communication.

"She doesn't produce a pretty, periodic sound when she performs these behaviors, like we do when we speak," Perlman added. "But she can control her larynx enough to produce a controlled grunting sound."

Specifically, Koko blows a raspberry into her hand when she wants to eat, can blow her nose into a tissue like humans, chatters aimlessly into a telephone, and even huffs moisture onto a pair of glasses before cleaning them. (Scroll to read on...)

[Credit: The Gorilla Foundation via Animal Cognition ]

Clearly these behaviors were born of imitation, but they also display an ability to achieve vocal flexibility gorillas weren't expected to have. Perlman suggests that Koko may have adapted to better interact with her caretakers.

"Presumably, she is no more gifted than other gorillas," he said. "The difference is just her environmental circumstances... She shows the potential ... for apes to develop quite a bit of flexible control over their vocal tract. It's not as fine as human control, but it is certainly control."

"Koko bridges a gap," Perlman added, suggesting that Koko's unique behavior bolsters the assumption that the groundwork for language development was in place even 10 million years ago, before the ancestors of humans and gorillas branched away to blaze new evolutionary trails.

The results of this study were detailed in the journal Animal Cognition.

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