Fundamental building blocks of language first emerged in human ancestors 30-40 million years ago, research suggests

Scientists tested ability of humans monkeys and apes to recognise the relationships between various sounds, writes Harry Cockburn

Chimpanzees Tina and Martin, who were studied at the National Centre for Chimpanzee Care in Texas (University of Warwick)

Language has been one of our species’ most fundamental breakthroughs, allowing us to communicate in extraordinary detail across an infinite range of subjects, so understanding its origins is central to our understanding of what it means to be human.

New research indicates our ancestors first began to build crude relationships between words as early as 30 million years ago. Today, our species flourishes by sharing thoughts, culture, information and technology through language — while no other species is known to be able to do so.

However, the fundamental early “building blocks” of language have been found in today’s monkeys and apes by scientists from the University of Warwick and the University of Zurich.

The researchers found apes and monkeys were able to track relationships between sounds the same way as humans, showing that this ability predates the evolution of language itself by at least 30-40 million years, they said.

The researchers believe they have made a crucial advance in our understanding of when this key “cognitive building block of language” may have evolved.

Being able to process relationships between words in a sentence is one of the key cognitive abilities underpinning language.

When the relationship between words is between two or more which are next to one another, it is known as an “adjacent dependency”. If the words are distant from one another, but still related, this relationship is known as a “non-adjacent dependency”.

The scientists use the example of the sentence “the dog who bit the cat ran away.”

“We understand that it is the dog who ran away rather than the cat, thanks to being able to process the relationship between the first and last phrases,” they said.

Dr Stuart Watson, who carried out this work at the University of Zürich, said: “Most animals do not produce non-adjacent dependencies in their own natural communication systems, but we wanted to know whether they might nevertheless be able to understand them.”

The research team used a novel experimental approach for their experiments. They created what they described as “artificial grammars”, in which sequences of meaningless tones instead of words were used to examine monkeys’, apes’ and humans’ ability to process the relationships between sounds.

This made it possible to compare the ability to recognise adjacent and non-adjacent dependencies between three different primate species, even though they do not share a common language.

The experiments were carried out with common marmosets (a Brazilian monkey), chimpanzees and humans.

The researchers found all three species were readily able to process the relationships between both adjacent and non-adjacent sound elements.

Non-adjacent dependency processing is, therefore, widespread in the primate family, the researchers said.

The implications of this finding are significant, said Professor Townsend.

“This indicates that this critical feature of language already existed in our ancient primate ancestors, predating the evolution of language itself by at least 30-40 million years.”

The research is published in the journal Science Advances.