From “The Observer” column of the Guardian, “There is no such thing as universal grammar”—
Language is possible due to a number of cognitive and physical characteristics that are unique to humans but none of which that are unique to language. Coming together they make language possible. But the fundamental building block of language is community. Humans are a social species more than any other, and in order to build a community, which for some reason humans have to do in order to live, we have to solve the communication problem. Language is the tool that was invented to solve that problem.
Also of note:
The lesson is that language is not something mysterious that is outside the bounds of natural selection, or just popped into being through some mutated gene. But that language is a human invention to solve a human problem.
Finally, on addressing his disagreements with Noam Chomsky and the notion of universal grammar, Everett notes:
My view of language could hardly be further from Chomsky’s. I try not to attack or to say intemperate things in the book, in spite of his attacks (on me). I don’t want to come across as someone who’s got a personal axe to grind. These are conclusions that I have reached after 30 years of work, and I think Chomsky is absolutely wrong about his most important claims, and I have tried to make my case with evidence. [emphasis added]