For thousands of years, humans have been obsessed with communicating with animals. So far, most of these efforts have been futile. However, when it comes to our cousins, the primates, there have been significant achievements, especially in sign language. Throughout history, many apes have been taught how to use sign language. Even though they were able to communicate with humans through signs, one must wonder – did they really understand what they were saying? That’s what we’re going to find out in this article.
How the Idea to Teach Apes Sign Language Started
To kick things off, humans initially wanted to teach apes how to talk like we do. However, this was impossible after it was discovered that apes do not possess the neural ability to comprehend human speech and control the vocal tract muscles.
All was not lost, though, as some brilliant minds observed that apes are well-versed in using hands and arms to communicate through gestures. That’s where the idea to teach apes sign language was conceived. For a long time, this hypothesis remained theoretical until Beatrice and Allen Gardner from the University of Nevada experimented on a chimp called Washoe.
The Experiment with Washoe and Other Chimpanzees
Before publishing a journal in 1969 that apes could learn sign language, Beatrice and Allen Gardner adopted Washoe when she was only 10 months old in 1966. They lived with her in their home in Nevada. Under the care of the Gardners, no one was allowed to talk. They could only communicate through American Sign Language (ASL). This couple was even forced to hire native ASL speakers to make the experiment a success.
By age five, Washoe could communicate more than 100 signs. She was sent to the University of Oklahoma Institute of Primate Studies for further experiments. Being the first to conduct a successful experiment on teaching apes sign language, the Gardners conducted similar tests on other infant chimpanzees, such as Moja, Pili, and Dar, which were all successful.
To make this study even more interesting, another chimpanzee called Loulis was introduced into this experiment. Her name was the abbreviation of her two caregivers, Louise and Lisa, who were based in Atlanta.
Loulis was raised by Washoe, not humans, as with other chimps that learned sign language. The most exciting part is that Washoe taught Loulis the American Sign Language. After just 8 days of living with Washoe, Loulis used her first sign. Eventually, she learned more signs from her mother, proving that apes can learn sign language, not just from humans but also from each other.
Later, the other apes, Moja, Pili, and Dar, were introduced to the family and cross-fostered. In this environment, all these apes would communicate with each other and humans through sign language. The study highlighted that only 5% of the signs used were food-related. More than 80% of the signs the apes used were about social interactions.
Subsequent Research on the Ability of Apes to Learn Sign Language
A single ape, Washoe, was the inspiration for many similar experiments. For instance, everyone remembers Koko, the famous gorilla who gave a climate change speech in 2015. On the contrary, Koko’s speech was quite controversial in the studies of whether apes can learn sign language. Because the video was most likely a compilation of utterances sifted through Koko’s life. Can an ape really understand the effects of climate change?
While pondering on Koko’s story, its worth mentioning another remarkable ape that contributed significantly to this field – Nim Chimpsky. Raised in Manhattan by Stephanie LaFarge, a student at the Columbia Univerity, Nim was taught American Sign Language from the get-go.
During this period, Nim learned more than 100 signs, including how to ask for marijuana. LaFarge was requested by one of her professors, Herbert Terrace, to run an experiment on Nim, which led to a study published in the Journal Science in 1979.
So, Can Apes Really Understand Sign Language?
This study, published in 1979, sparked doubts about whether apes understand sign language because there is footage of apes making signs prompted by images or frames. Therefore, there is a possibility that these apes are just mimicking human behavior and could potentially have no clue what even these signs mean.
The purpose of sharing studies on different apes and their experience with sign language is to highlight the strengths and weaknesses of the above hypothesis. In some ways, it seems that apes can learn sign language. However, can they efficiently use it? Probably not!
Even with apes such as Washoe learning hundreds of signs, grammar was a big problem for them. When asking for a banana, she would play around with lots of other words. Same case with Koko and Nim. It was up to the handlers to carefully sift through these signs and decode the main message.
The Key Takeaway
It’s safe to say that these apes, which were obviously in captivity and away from their habitat, had to learn sign language to have the ability to ask for things from their human caregivers. On the bright side, gorillas such as Koko could devise new signs by compounding two or more signs from familiar words, indicating that apes are brilliant creatures.
Whichever the case, this is a significant breakthrough in science! Because unlike things were a century ago, today, humans can use sign language to communicate with apes, even if there are several barriers.