Researchers have long been trying to pinpoint why great apes, with the same vocal equipment as humans, do not have language in the human sense. Recently, a team headed by Vanessa Wilson from the University of Neuchatel, Switzerland, published an interesting result:

When watching a cat chase a mouse, humans will alternate looking at cat and mouse, using the information to connect the two into what’s called an agent-patient relationship — with the cat as the agent and the mouse as the patient. This cognitive mechanism is thought to be one of the bases for the evolution of human language, forming both how people think about events and structure speech. 

PLOS Biology. “Great apes visually track subject-object relationships like humans do, study finds.” Science Daily, 26 November 2024

Their study of five chimpanzees, two gorillas, and two orangutans at the Basel Zoo, along with 29 human infants, showed that apes can discern an agent–patient relationship but that human infants tend to be more interested in the background:

The authors found that both apes and adult humans paid the most attention to the agents and the patients compared with background information. They often alternated attention between the two, focusing more on the agent when video clips involved food. Humans tended to focus entirely on the agents and patients, while apes showed more attention to the background. But while apes tended to track events like human adults, six-month-old human babies did not, instead paying attention mostly to the background. 

“Like humans do”

Their conclusion?

The findings suggest that the way brains order events evolved before language, and that the way people break down events into agents and patients is not unique to humans, but instead is part of a cognitive spectrum between humans and other great apes. 

“Like humans do”

From the Abstract:

These findings raise the possibility that event role tracking, a cognitive foundation of syntax, has evolved long before language but requires time and experience to become ontogenetically available. 

Vanessa A. D. Wilson, Sebastian Sauppe, Sarah Brocard, Erik Ringen, Moritz M. Daum, Stephanie Wermelinger, Nianlong Gu, Caroline Andrews, Arrate Isasi-Isasmendi, Balthasar Bickel, Klaus Zuberbühler. Humans and great apes visually track event roles in similar ways. PLOS Biology, 2024; 22 (11): e3002857 DOI: 10.1371/journal.pbio.3002857 The paper is open access.

But What Did They Really Find?

Are we supposed to believe that, watching a cat stalking a mouse, a great ape might not be expected to guess which was the “agent” and which was the “patient” — and know how to understand what is happening? It would be interesting to see the results from a study of alert dogs and cats. Six-month-old human babies, of course, don’t show the same responses because they don’t “get” that a hunt is in progress. It’s all just movement to them.

Surely, any adult animal life form needs to know the difference between predator, prey, and neutral background just to stay alive. So if “event role tracking” evolved long before human language, a logical conclusion is that the essential elements required for human language are of a different order than basic survival skills like that. 

Of course, human language must incorporate such skills and they are likely embodied in subject–object grammar (“The cat almost caught the mouse.”) But then so are a lot of other concepts with a similar grammatical relationship embodied in that grammar, like “We hold these truths to be self-evident… ” — concepts that take us right out of the animal world altogether.

What’s revealing in these types of studies is not what the researchers find but what the science media choose to make of them. At Popular Science, Tom Hawking writes,

Like many animals, apes clearly communicate with one another, and the ways in which they do can be startlingly human-like: They take turns to vocalize, interrupt one another and have individualized voices. Nevertheless, their communication lacks the complexity that characterizes human language. It seems that being able to communicate more effectively would provide an evolutionary advantage — so if they possess the cognitive framework to evolve language, why have apes not done so? 

“Great apes may have cognitive foundations for language,” November 27, 2024

Actually, dogs and cats vocalize, interrupt, and have individualized voices too. They do not “speak,” in the human sense, either. There is a vast gulf fixed, and it is not between primates and other mammals; it is between humans and all other life forms.

And yet Hawking goes on to say, after a discussion of various possibilities as to the reasons:

Ultimately, though, the more we learn about animals and the ways in which they communicate—and the cognitive mechanisms that underlie those forms of communication — the more we come to understand that humans are perhaps not as unique as we might like to think we are. “In short,” says Wilson, “we are finding more and more that the difference between human communication and that of other species is one of degree, rather than kind… I would say that at this stage, our understanding of the possible drivers of communicative complexity is still just at the tip of the iceberg.”

 “Cognitive foundations for language”

And what she says is the exact opposite of the direction in which the findings clearly point: There is something exceptional about human language that cannot be explained by the comparative ability of a chimpanzee and a human to follow a video of a cat and mouse chase.

One conclusion looms: Not only aren’t researchers making much progress understanding the origin of human language but perhaps they can’t. That could be because the origin is inevitably shrouded in mystery. Alternatively, there are things we could certainly learn but not if we can’t accept the most basic reality, fundamental to progress: Human language is exceptional. 

In this matter, evolution is a ladder with no lower rungs.

Cross-posted at Mind Matters News.