Simple puzzles are revealing why humans are the only talking apes

Cognitive scientist Gillian Forrester is challenging chimps and gorillas to solve puzzles in an attempt to address the long-standing mystery of how humans evolved the ability to speak

By Alison George

IT LIES at the centre of human experience, and yet how our incredible capacity for complex language arose is a mystery. We are still far from understanding why we are the only living ape with such a skill.

Answering these questions is difficult, not least because speech doesn’t leave its trace in the fossil record. However, we can look to our ape relatives for clues, as cognitive scientist Gillian Forrester at Birkbeck, University of London, is doing. She has developed puzzle mazes for chimpanzees, gorillas, orangutans and children that shed light on one idea of how language evolved. She tells New Scientist how her findings are challenging our understanding of the brain and painting a clearer picture of how language began.

Alison George: What inspired you to study the evolution of language?

Gillian Forrester: I’ve always been intrigued by the efforts to teach chimpanzees to speak, which were going on while I was growing up in the 1980s. They were a massive failure when it came to chimps learning to combine words into more complex phrases.

This got me intrigued about the common factors between human language and other animal communication systems, and how and why a language system emerged in humans but not for other great apes.

How do we start to answer that question?

We don’t have our ancient ancestors to look at to see how things changed over evolutionary time because they are all extinct, and cognition doesn’t fossilise. So all we can do is make suppositions based on their artefacts, such as tools and things they were buried with, to give us an indication of their communication skills. …