Many evolutionary anthropologists and linguists believe that linguistic recursion is a unique feature of human language capability. Linguistic recursion is the inclusion of clauses within clauses in a grammatical sentence or proposition (see 1, 2, 3, )
In the following sentence, the clause {1} is single recursion embedded within the sentence:
"The Cowboys won the baseball game, {1} which I thought they would lose, by a score of 5 to 3".
In the version of the sentence below, there are two recursions, {1} and {2}:
"The Cowboys won the base ball fame, {1}which I thought they would lose, {2}because their star left-fielder couldn't play, by a score of 5 to 3".
Clause {2}, though embedded within the whole sentence, is also embedded within clause {1}.
There are various arguments why nonhumans and early hominins could not have had a true language in the sense of not having linguistic recursion in their signaling language. One reason is recursion requires a large working memory, which, it is believed, only modern humans have. To use and comprehend recursion, an animal would have to hold two or three simultaneous thoughts in its mind. Such capability would require a working memory with at least several dedicated neuronal sets and it is not clear animals have such brain capacity. Another reason is that ethologists have not observed nonhumanoid animals to express communication with recursion.
However, the question needs to be asked whether recursion could appear in behavior first, then later in vocal or signaling communication. Certainly, some animals are capable of behavioral recursion. A dog can be observed to go from place A to place B in a landscape. Mid-route, the dog interrupts its journey to do something else, perhaps investigate a scent discovered on a mound of dirt. After it has investigated the scent for a few seconds, it returns to its prior task of trekking to place B. From the point of view of the entire journey, once completed, from place A to place B, the interruption involved in smelling the mound of dirt was recursive behavior. How such recursive behavior is to be explained is a matter for the scientists, but we can assume it involves intention (to get to place B) and memory (remembering the intention). Once the journey is completed, the dog has a chain of memories (having the intention to go from A to B, starting the journey, interrupting the journey, resuming the journey, arriving at B). Rehearsal of this memory by the dog would require activation of recursion in the replay of memories.
Such behavior almost certainly existed in and exists today in animals which have mental maps to guide behavior. We have already seen decisive evidence that, for instance, bees and cows have mental maps. As mental maps are symbolic and representational, when a bee or cow uses a mental map to guide it in a journey, a behavioral recursion can possible alter the map. Thus, a bee heading toward a field of flowers might be drawn to a tree of flowers, perhaps by stronger stimulus, only later completing its original journey to the field of flowers. If the bee communicates the location of the blossoming tree to the hive, then it has successfully altered its mental map, making the map more complicated, with a behavioral and symbolic recursion.
With the existence of behavioral recursions established (we are assuming, of course), the issue then becomes how the behavioral recursions, which have symbolic form in mental maps, are communicated to other organisms, presumably within the same hive/pack/species. The presumption should be against the notion that such communication is impossible. Communication is the expression by one form of behavior of symbolic mental maps obtained by a different form of behavior--of linguistic acts communicating the symbols involved in mental map memories obtained by behavior acted out on a landscape.
Comments