When asked about the greatest innovation of humans, people will often say language or fire. A new paper suggests that these innovations may be more interlinked than we thought.
Understanding how human language evolved is one of the hardest problems in science to unpick, since writing is a relatively recent innovation. The vocal tracts and brains of our ancestors did not fossilize, as they were made of soft tissue. We are left, then, with indirect evidence, such as how humans and other apes communicate today.
A leading theory about the origins of language is that our ancestors first communicated using gestures. This theory is based on what we know about apes: evidence suggests both chimpanzees and gorillas have gestural communication systems.
If human language started with gestures, then why are the vast majority of languages today spoken? The answer might lie in the limits of gestures. You need light to see a gesture, and our ancestors would have needed to communicate after dark.
In the new paper, researchers at the University of St Andrews argue that the dim light of a campfire might explain why we moved from gesture to spoken language. Firelight may be too dim to carry the detailed signals of early gestural language. To tell fully expressive stories in the dark, we would need spoken language, while still keeping gestures to emphasize our words and show emotion.
The researchers highlight how storytelling links to some of the features that make human language unique. Stories have complex structures and are often displaced in time and space, meaning they talk about things not immediately present, in the past, or sometimes not even real.
The paper suggests that social storytelling enabled us to move beyond the communicative abilities of other living apes. Storytelling aids our social bonds and helps us understand the world and how to behave. It can also help us develop our imagination, identities, and cultural beliefs.
The idea that language emerged for social bonding is not new. However, the authors highlight that the fireside setting might have been crucial. They argue that the color spectrum of fire is well suited to human vision and does not suppress the melatonin that helps us sleep, as modern screen light can.
They also point out that human neurons synchronize to the frequency of flickering firelight. The authors argue this can improve bonding through shared rhythmic activities that can promote empathy.
Other research has shown that stories from our early oral traditions share similar traits. This is thought to happen because the social transmission of stories acts like evolution. Instead of survival of the fittest, we get survival of the most memorable parts of stories. Stories tend to survive when they have more social, human-focused content, include surprising elements, stir negative emotions, or deal with survival.
Researchers think this is because swapping stories about social bonds, unexpected dangers, and survival is advantageous for our evolution. Storytelling is still one of the main ways we make sense of the world.