The Symbolic Species: The Co-evolution of Language and the Brain (1997) by Terrence Deacon, a neuroscientist and evolutionary anthropologist is a great book. Here is an independent thinker with an abundance of commonsense writing about the core issue of language and evolution. It has been more than twelve years since I began my love affair with this book that lies open before me with its spine broken, pages curled, and the first blank page covered with my annotations. I took away two messages from Deacon, who is now in California. The first is the enormous gulf between learning by association, whereby some dogs can have a vocabulary of more than two hundred words, and symbolic language.
A cylindrical graph from the book is planted in my mind. The learning of words associated (indexed) to objects in the world is represented by cylindrically arranged arrows pointing from the words in the mind down to the objects. That is what dogs can do; they can associate words with objects. Then the next step is to map the relationships that the objects have with each other in the world onto the words, which dogs can also do. Saying “ball” is related to the word “door” in order to go outside, which is also related to the word “stick,” which is as good as a ball. This is represented by a network of transverse arrows connecting the tops of the perpendicular ones arranged in a second cylinder that still all point down to the objects. So, in the dog’s mind, the words are connected in a network that represents their relationships in the dog’s experience. All of the dog’s knowledge of these relationships flows back to the words and down through the two cylinders of arrows pointing down to the objects they represent in the physical world.
But now there is a canyon that must be leaped across in order to achieve what Deacon consideres true symbolic language. A third cylinder of arrows must be placed above the first two. The flow of the associations between the words directly down to the objects to which they refer must be interrupted. A new, higher reference to memorize now becomes the rule-bound (grammatical) relationships between the words. The arrows of memory are now reversed at this higher level so that the real-world physical relationships between words at the top of the second cylinder must obey the grammatical relationships between them at the top of the third cylinder. In true language, the real-life relationships between words must first fit into the grammatical rules between words before they can be expressed. Humans can do what dogs can do, which is relate objects to words and remember the associations between the objects they represent, but what dogs (or chimps) can’t then do is to both express and understand these real-world associations between words while simultaneously following the rules of grammar.
The take-away message for me was that symbolic language is fundamentally relational, which fit into my original thinking about the role of relational genes between dominance and submission mentalities. The fact that human language involved the interaction between two kinds of relationships between words, one in the real world and one according to a set of rules, reinforced that the human mind contained the interaction between two separate mental entities.
The second idea that I took away from this marvelous book chock full of creative thinking was the speculation that the push to evolve symbolic language came from monogamous pair-bonding, which Deacon felt occurred in the early species of the Homo genus 2.5 million years ago as indicated by the reduction in size differences between males and females:
“The first requirement, then is that there must be a means for marking exclusive sexual relations in a way that all members of the group recognize . . . Sexual access is a prescription for future behaviors. No index or memory of past behaviors can represent this . . . The pair-bonding relationship in the human lineage is essentially a promise, or rather a set of promises that must be made in public. These not only determine what behaviors are probable in the future, but more important, they implicitly determine which future behaviors are allowed and not allowed; that is, which are defined as cheating and may result in retaliation.”