Much has been made about the linguistic ability of Koko the gorilla.
The 44-year-old gorilla may be most famous for her interaction with the late actor and comedian Robin Williams. In the video below, Koko and Williams are seen playing around, seemingly teasing each other and communicating through laughter during a visit Williams took to meet Koko in 2001.
But now researchers are exploring something else: the possibility that mammals other than humans are capable of speech. As it stands, there is a general consensus that apes are not capable of performing any communication that resembles speech. That was until a July study published in the journal of Animal Cognition questioned whether Koko was performing voluntary behaviors that resemble speech.
According to the University of Wisconsin-Madison report, Koko has "nine different voluntary behaviors that required control over her vocalization and breathing." They added that these behaviors were learned, and in no way part of the average apes' repertoire.
"I went there with the idea of studying Koko's gestures," Marcus Perlman, now a postdoctoral researcher in the lab of University of Wisconsin-Madison, told the publication. "But as I got into watching videos of her, I saw her performing all these amazing vocal behaviors."
The research added that the nine actions they observed "involve variable coordination of her breathing, larynx, and supralaryngeal articulators like the tongue and lips." Being that these are all things involved in creating speech, it is not unreasonable to make the leap Koko is capable of forming a word or words.
But beware of the nuances...
Koko's linguistic ability is and has been quite controversial.
As Slate author Jane C. Hu discussed, it's quite possible that when we see Koko communicate with humans, or hear about her "mourning" the death of Robin Williams, we are simply projecting ourselves onto the ape and not considering what Koko's intentions are with her behavior.
On top of that, it should be noted that humans are equipped with an anatomy that makes speaking possible, an anatomy that apes don't currently possess. That's why early on in the research of communication between apes and humans, human researchers switched to teaching sign language.
That innovation succeeding in bridging a gap, but failed to prove apes were even interested in talking. As psychologist Susan Goldin-Meadow discovered while studying Kanzi the bonobo, only 4 percent of her signs were "commentary." The other 96 percent were all communicating needs, like asking for food or water. In other words, apes aren't picking up on the same kind of social cues that humans might, and certainly not going out of their way to make small talk.
Yet, seeing Koko cough on demand — which requires closing off the larynx — can get the imagination going.
"Koko bridges a gap," Perlman added. "She shows the potential under the right environmental conditions 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."
It's fun to imagine apes on the brink of speaking, but for now all we can really know for sure is that they are capable of understanding sign language and may have more control over their mouths and throat then we originally thought. The rest, as has been noted, is up for much debate.