Old videos of chimpanzees suggest they are capable of speech

A small team of speech specialists and psychologists from Sweden, the U.K. and Switzerland has found, via study of old videos, that at least three chimpanzees had learned to speak human words, suggesting that the animals are capable of learning this ability given the right circumstances. The work is published in the journal Scientific Reports.

Over the past several decades, scientists have wondered why humans are the only primates that have evolved speech. While it is true that some great apes have learned to communicate via vocal sounds, there is little evidence that they use a spoken language.

Because of that, a debate has emerged between researchers who believe the difference lies with throat physiology versus those who believe it is due to differences in the brain. Others have suggested that some great apes, such as chimpanzees, do possess the ability to speak human words, albeit at a rudimentary level.

The researchers provide one notable example of a husband–wife team who adopted an infant chimp and kept it in their home for several years, trying to coax it to say simple words, such as "mama," "papa," or "cup." But their work was discredited over the years as unethical because the chimp was taken from its natural mother.

In this new effort, the research team wondered if dismissal of these findings was done in absence of attempts to duplicate their efforts. To find out if that might have been the case, they searched for video evidence of such attempts at training and found three videos showing evidence that chimpanzees can be taught to speak human words in a rudimentary way.

In one video made by the husband–wife team, the chimp spoke the word "papa" at least three times and the word "cup" once. In another video on YouTube, a chimp (Johnny) spoke the word "mama." And another video from Italy captured a chimp saying the word "mama."

The researchers note that the chimps' pronunciation varied from human speech, but describe the speaking attempts as "essentially word-like," a finding that they suggest indicates that great apes are capable of speaking some human words given the right circumstances.