The Flaws in His "Origin of Language" Experiment

In 2017 Evolutionary biologist Kevin N. Laland produced a book entitled “Darwin's Unfinished Symphony: How Culture Made the Human Mind.” The book had an odd subtitle. How could culture have made the human mind, when a mind like the human mind was needed for culture to have even got started?

Chapter 8 of the book is entitled, “Why We Alone Have Language.” Laland presents a theory of the origin of language, but it's not a very useful one. His theory addresses the “why” of the origin of human language, not the “how” of the origin of human language. Anyone can come up with reasons why humans might have found it useful to originate a language. The hard part in regard to the origin of language is explaining the “how” part. This involves addressing questions such as these:

• How could a language ever have got started, when it seems that you need to have a language in place in order to teach anyone a language, or to impose a language on a group of people, so that they all speak the same language?
• How could a language ever have got started, considering that language requires lots of specialized speech biology in the mouth and brain, which wouldn't have existed when someone first tried to establish a language?
• How could anyone have contrived any original rules of grammar, the origin of which is so much harder to explain than someone merely thinking up some nouns and words, and convincing nearby people to use those words and nouns?

Laland's theory of the origin of language is that language was created to teach people things. Laland specifically suggests that language was created so that people who knew how to make stone tools could pass on that knowledge. To try to back up this idea, Laland has done some experiments. He had 200 adult experimenters work in experiments described in his book as follows:

Adult human participants first learned to knap stone flakes using a granite hammerstone and flint core, and then were tested on their ability; next, they helped others learn this skill....Experimental subjects were allocated to one of five conditions that varied according to the type of information that could be passed from “tutor” to “pupil.”

The five conditions included an “imitation” condition in which pupils could only imitate another person they were watching, a “gestural teaching” condition in which a teacher could only silently make gestures to try and teach how to make stone tools, and a “verbal teaching” condition in which teachers could speak instructions to their pupils. The experiments showed that teaching someone how to make stone tools occurs more effectively when you can use language such as modern English – but only slightly so. A scientific paper describing the experiment says in Table 1 that the “total quality” of the teaching of how to make stone tools was 23.6 with verbal teaching and 19.8 with gestural teaching.

Laland sounds very pleased with his experimental results, and at the end of the chapter, he makes it sound like they offer some evidence of great importance. He says this:

Alfred Russel Wallace, codiscoverer of natural selection, famously failed to accept that selection could account for human evolution, partly because he could not imagine how a trait like language, and the other unique features of human cognition, could evolve. I would like to believe that, had he known of the material in this chapter, he might have reached a different conclusion.

But Laland has failed to see two fatal flaws in his experiment. I can explain the first flaw by mentioning that humans can only speak clearly because of a great deal of specialized biology, biology which humans would presumably not have had when the first humans tried to speak. This biology is mentioned on page 174 of the book How Language Began by Daniel L. Everett, who states the following:

The creation of speech requires precise control of more than one hundred muscles of the larynx, the respiratory muscles, the diaphragm, and the muscles between the ribs – our “intercostal muscles”-- and muscles of our mouth and face – our orofactal muscles. The muscle movement required of all these parts during speech is mind-bogglingly complex.

And here Everett is not even mentioning specialized biology in the brain. Stroke victims often lose much of their ability to speak. So there is not only a good deal of the brain specialized to allow speech, but also a good deal of speech-specialized biology in the area around the mouth, throat and lungs. There is no natural reason why humans would have had so much speech-specialized biology when humans first started to speak.

The flaws in Laland's experiment are as follows:

1. He has compared the effectiveness of gesture-teaching of stone making skills to the effectiveness of speech-teaching of stone making skills, using modern humans who have mouths and brains optimized for speech. When language originated, according to naturalistic assumptions, humans would not have had such biology.
2. He has compared the effectiveness of gesture-teaching of stone making skills to the effectiveness of speech-teaching of stone making skills, using modern humans who could use the full grammatical amd vocabulary richness of modern speech. When language originated, according to naturalistic assumptions, no such linguistic richness would have existed.
3. His experiment only allowed a five-minute teaching period, which did not allow any “hand gesture” teachers a decent amount of time to teach some hand signals to be used in the instruction.

I can imagine how you could modify Laland's experiment to get a more realistic result. The first change in the experiment would be for all the "speaking allowed" teachers to have had mouths filled with food when they tried to teach how to make stone tools. This would simulate the fact that the first people trying to use spoken language would not have had any mouths optimized for speaking, and would only have been able to speak garbled words, making the kind of hard-to-understand sounds a person might make if his mouth was filled with food.

A second modification in the experiment to make it more realistic would be to forbid the teachers from using any language other than a language they invented themselves. So, for example, a teacher might be allowed to invent the word “crob” to mean “rock,” and then to teach that word to someone; and a teacher would be allowed to invent the word “soz” to mean “strike,” and then teach that word to someone. But a teacher would not be allowed to use instructions such as the English sentence, “Now firmly grip the big stone with your left hand and strike it at a 45 degree angle with the smaller stone, using your right hand.” The third change would be to allow all subjects to have up to an hour to teach, allowing someone a decent length of time to teach some hand signals or newly invented words that could later be employed as part of the instruction.

With these three modifications, the experiment would realistically simulate whether  it would be more effective for teachers at the beginning of a language's origin to teach using hand gestures or using rudimentary speech. The experimental results would be drastically different. Instead of finding that the teachers trying to use speech were slightly more effective than the teachers using gestures, it would be found that the teachers using gestures were able to teach much more effectively.

Why is that? It's because it's much easier to convey information using nice, clear hand signals than by using spoken language whenever spoken language sounds all garbled and unclear, as it would have sounded if humans first started to use spoken language before getting all the specialized biology in the mouth and brain allowing spoken language to be clearly transmitted.

There is a paradox I call the IPS paradox. IPS is an acronym standing for Inferiority of Primitive Speech. I can describe the paradox or difficulty as follows:

1. Before any spoken language, it would have been possible for humans to communicate fairly effectively and clearly using hand gestures, in which particular words are expressed by particular hand gestures.
2. If humans first started speaking before developing all the specialized biology needed for clear speaking, they would only have been able to speak in a very unclear and garbled manner, like a modern person trying to speak while holding his tongue against the bottom of his mouth, or trying to speak with a mouth filled with food.
3. Such a primitive mode of oral communication would have been greatly inferior to hand gestures as a mode of communication.
4. It therefore seems that oral language never could have become established before organisms developed good speech biology like modern humans have, and that there would never have been any gradual progression from primitive, garbled speaking to the type of clear speaking like humans now have.

I argued for this Inferiority of Primitive Speech paradox in a previous post. Laland's experiment does nothing to remove that paradox. His experiment allowed people with modern anatomy to use regular English sentences to teach stone-making. That does nothing to clear away the difficulty that it would have been a hundred times harder to orally teach something at the dawn of language, at a time when human ancestors did not have all the nice biology current humans have allowing them to speak clearly, and when no language was yet established. The Inferiority of Primitive Speech paradox is a powerful reason for rejecting all theories of the naturalistic origin of human spoken language. We can understand how humans might have naturally developed a hand gesture language, but cannot understand how humans could have naturally developed the first spoken language with rich expressive capability and complex rules of grammar.