What sets us apart from animals that share 98.8% of our DNA? There may be many different and valid answers, but one that always comes up is the inability of chimpanzees to speak.
There are two theories as to why chimpanzees may not be able to make human speech sounds. This disability may be related to physical limitations and the inability of their lips, tongue or mouth to speak. Some also think that chimpanzees lack the neural pathways necessary to produce complex sounds.
However, in a new paper, researchers have challenged the idea that chimpanzees do not have the building blocks of speech by examining some old movies. At the same time, animals sometimes imitate human speech, even if they do not have the same vocal equipment. For example, whales and marine mammals can imitate sounds.
In human babies, words like “mama” (meaning mom in baby language) are often among the first words uttered. The researchers looked at old videos of two chimpanzees, Johnny and Renata, each saying the word “mama.” The authors explain in the article that Johnny lived at the Suncoast Primate Sanctuary in Palm Harbor, Florida, in the United States. In a recorded home video, Johnny appears to be confused when asked, “Can you say mom?” gives the correct answer.
In the case of Renata, the video from Universal Studios’ World Newsreels, “Now Hear This! Italians Reveal Talking Chimpanzee” was published in 1962. However, no information has been found about Renata’s life or how she was taught to speak.
In the past, scientific studies conducted on monkeys were not ethical and would probably not pass the test of today’s ethical standards. The “ape language” studies included traumatized monkeys whose emotional, environmental, and social needs were not met and who suffered psychological trauma. Many of these monkeys were taken from their mothers in the wild and were treated with neglect and cruelty. Today, such actions do not meet ethical standards. Probably, the results of this research are not very quotable.
The researchers conducted an experiment to test whether neutral people unfamiliar with the study could understand what the chimpanzees were saying. The chimpanzees’ voices were mixed with those of humans who had speech impairment from Parkinson’s disease. Each voice said only a few words, and study participants did not know that two of the sounds belonged to chimpanzees. Participants were asked to write down the words spoken during the experiment. If they write ma or mama, it shows that the sounds chimps make are similar to human words.
In the study, most participants agreed that Renata was making the “midwife” sounds, while there were mixed reactions to the sounds Johnny was making. These results show that chimpanzees are capable of vocal learning.
“Chimpanzees can produce the putative ‘first words’ of spoken languages,” the research team wrote. Interestingly, the lack of discovery of this ability decades ago was due to the lack of researchers, not the inability of animals. Chimpanzees have the neural pathways necessary for speech.
However, this research has not convinced everyone. Julia Fishera cognitive scientist at the German Primate Center in Göttingen, explained to the New York Times: They do it with sound, it has nothing to do with human speech.” He believes that apes’ voices are fundamentally different from human speech, and in the ongoing debate over “ape language,” the newly published paper is an example of a battle between differing views.
The researchers’ article has been published in Scientific Reports.
