ing information. Unlike emotional signals, the form of which is fixed, the form of a word is arbitrary. A person can say tree, tree, der baum, el árbol, il arbero, or their equivalent, in over 6,000 spoken languages, or in gestures used in dozens of sign languages.
In sum, the shift from emotional signals from animals to words involved a larger change in form of expression than the shift from words to grammar. These only concern their organization, order, inflection, etc. The shift from animal communication to words marks the first time our ancestors communicated in a conversational, arbitrary fashion. This is not to minimize the importance of the passage from words to grammar but only to clarify that it does not require a new form of expression.
Despite these apparent facts about words, they remain stepchildren in discussions of the evolution of language. As mentioned earlier, the vast literature on the evolution of language has focused on grammar, not words.
Source: Wugapodes / Wikimedia
This imbalance can be attributed to Chomsky and his students. For more than 70 years, they have sought to discover the nature and origins of grammar, possibly at the expense of words. As can be seen from a recent comment, Chomsky seems to be aware of this problem:
The minimal meaning-carrying elements of human languages… are radically different from anything known in animal communication systems. Their origin is entirely obscure, posing a serious problem for the evolution of human cognitive capacities, in particular of language.1
I recognize the importance of understanding grammar and why a theory of grammar would be the ultimate step in explaining the evolution of language. But neglecting the origin of words in the quest to understand the origin of grammar seems to me to put the cart before the horse. It’s like trying to understand molecules without understanding the nature of the elements and the atoms that define them. Just as the efforts of alchemists to transmute lead into gold have hampered our understanding of chemistry, ignorance of the origin of words hampers our understanding of language and its functions.
Focusing on words rather than grammar, however, reveals an interesting problem. Linguists have yet to agree on the definition of a word. Culturally, linguists consider all individual statements in the form of words. This is true for humans as well as for animals. Children’s statements such as hi, no, up, ouch, over, bye, etc. are considered words. The same goes for the statements that monkeys learned in experiments about “language” and the signals of animals to communicate. For example, the alarm calls of vervet monkeys, eagles, leopards and snakes have been mistakenly called words.
What is needed is a definition that will distinguish between these statements and the referential properties of words. This is why I define words as arbitrary statements that are used in conversation. Speakers use words to denote objects or events for the benefit of a listener and vice versa.
This definition provides an important evolutionary limit that preserves the essence of human language. It can violate deeply felt cultural biases by excluding a tiny number of statements infants make, statements that are not referential. But language as we know it would never develop if such utterances were all a child could learn.
To recap, I argued that the best way to advance in the evolution of language is to focus on the origins of words, not grammar. This effort must be both phylogenetic and ontogenetic.
From a phylogenetic point of view, it is important to ask what psychological and environmental factors facilitated the shift from animal communication to words?
Ontogenetically, we must ask ourselves, how do the utterances of human infants become words of reference?