In this review of James R. Hurford's The Origins of Grammar, Nick Enfield presents a significant viewpoint on how we humans, from a stage when our ancestors were without language, came to acquire language in all its modern complexity.
If you could travel back to a time around the dawn of humankind, and if you encountered a people there whose only form of language was a list of one-word interjections like Yuck, Wow, Oops, Hey!, No, and Huh?, would you say that these people were of a different species, not quite human? Would they be like today’s apes that simply don’t have it in them to fully acquire a modern human language? Or would they be the same as us only less well equipped for communication, like the eighteenth-century man who is every bit human but happens not to have been born in a world with telephones? If the latter were true, then language would be more technology than biology, more something we build than something that grows. It’s clear that the earliest humans did not possess language as we know it. The question is whether this was because language as we know it hadn’t yet been invented.
In James R. Hurford’s towering account of our species’ path from being once without language to now being emphatically with it, he proposes that just such a monophrase language of the Yuck/Wow variety was an important early human achievement. And, Hurford argues, while our earliest forms of language had no grammatical rules by which words were combined to form sentences, they were far from primitive call systems.