 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?