Features of human language

To theorize about the evolution of human language is to theorize about how human communication differs from the communication systems used by other species, and what biological basis underlies these differences. The features of human language that I would suggest we need to account for are as follows:

• Syntax: Human language is compositional, conveying structured meanings through the use of structured forms.

• Learning: Human language is passed on from one generation to the next via cultural transmission.

• Symbolic reference: The mapping between basic lexical elements and their meanings is arbitrary and conventional.

In distinguishing human language from other forms of communication, the attention has largely been focused on the evolution of syntax (Bickerton, 1990; Pinker and Bloom, 1990; Newmeyer, 1991). This is unsurprising, as syntactic structure is certainly the most salient feature of human language. Because other species seem to have no means of combining simple signals with each other to form more complex meanings, the prime objective of most research on the evolution of language has been to explain how such an ability arose in humans.

In this chapter, I will instead focus on the other, perhaps more basic, features of human language that make it unique – learning and symbolic reference. While there are other forms of communication that are learned, and there are other forms of communication that are symbolic, I will argue that human language is the only existing system of communication that is both learned and symbolic. Moving from a simple (non-syntactic) innate system of communication to an equally simple learned system is non-trivial.