2 - Evidence for evolution

Summary

Overview

Evolutionary linguistics presupposes, by its very name, that it is appropriate to think about language in evolutionary and not just historical terms, and that some structure or structures underlying modern human languages must therefore have evolved somewhere in the family tree of our species. In this chapter, however, we unpack that presupposition, considering evidence from a range of areas to support the suggestion that some aspects of this capacity for language have indeed evolved in humans. This evidence involves the biological argument from design; the hypothesis that there is a critical period for language acquisition; Chomsky’s famous argument from the poverty of the stimulus; evidence from children’s creativity, especially in the context of creolisation; the notion of specialised language areas in the human brain; and finally, the identification and tracking of genes where defects inherited in families appear to correlate with language (and often other) difficulties.

The argument from design

There are two logically possible but extreme views on the origin and evolution of language (we return to the more habitable but debatable land between them below). The first of these would claim that language is genetically specified and inherited in every particular; the other would argue that language is learned from what is available in the environment, again in every particular. Like most diametrically opposed and absolutist positions, both are demonstrably wrong.