Orangutan "Kiss Squeaks" Could Give Insight Into Evolution Of Human Language


The way orangutans communicate could help us understand our own language. Zenzatographer/Shutterstock

One of the most persistent mysteries about our own species' evolution is the development of complex language. How we managed to move from making simple grunts to advanced sentences in which we can now convey any information through words, is difficult to deduce. One study, however, claims to show how specific orangutan vocalizations may shed light on the origin of our own language.

By analyzing thousands of so-called orangutan “kiss squeaks”, researchers from Durham University have found that the apes combine these noises, which are formed in a similar way to how we make the sounds of consonants, to communicate different meanings. They think that this could show how from rudimentary noises, ancient humans could have developed a far more advanced and complex language system.


“We tend to think that maybe words evolved from some rudimentary precursor to transmit more complex messages,” explained Dr Andriano Reis e Lameira, who co-authored the paper published in Nature Human Behaviour, to BBC News. “We were basically using the orangutan vocal behavior as a time machine – back to a time when our ancestors were using what would become [those precursors] of consonants and vowels.”

The apes use a wide range of vocalizations, from booming bellows that can be heard miles away to “grumphing” noises when close to each other. But it was another sound that interested the researchers, known as a "kiss squeak" due to how the orangutans make it. In a similar way to how we make the sounds of consonants, the kiss squeak is not produced due to the voice, but instead through the actions of the lips, tongue, and jaw.

Listening to thousands of hours of communication between the 48 apes living in four populations in the wild, they found that the orangutans were combining the kiss squeaks in different ways, in what the researchers say is a similar way to how we have multiple words to convey a single meaning. They report that the orangutans were essentially communicating the same thing in different ways by altering the pattern of kiss squeaks.

This means that opposed to our ancestors making an active choice to make complex words, the redundancy built into the way orangutans communicate with kiss squeaks could offer a way that the complexity emerged organically.


[H/T: BBC News]


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  • evolution,

  • vocalization,

  • orangutan,

  • language,

  • early human,

  • proto-language,

  • kiss squeak