Descartes explained the mechanical structure of the brain as controlling memory, association, and habitual bodily responses, but he famously denied that a machine (or anything composed of physical matter) could ever realise human language. Descartes considered it physically impossible that a physical structure could ever be capable of the spontaneity and variety of human speech.
Today, we are faced with a different, yet still fundamental question: do innate structural characteristics of the brain determine the grammatical shape of human language? If not, then how do culture and community have the power to transmit grammatical shape across generations?
During the 20th century, this question evaded adequate answer. But in a recent study published in Nature (and discussed recently on the BBC), several psycholinguists and cognitive scientists believe that they have shown that the nativist argument– that the structure of the brain determines the grammatical shape of human language– is false. The study does this by first isolating four different ‘family trees’ of human languages– Bantu, Indo-European, Uto-Aztecan and Austronesian, and then addressing whether or not the different language structures inherent in these family trees can be explained by appeal to a universal set of rules. The result, claim the authors, is that we can far better account for the structural differences in these languages if we instead treat them as being akin to genetic traits possessed by the community of speakers, transmitted generation by generation, as opposed to being shaped and constrained by a specific module in the brain.
If the methodology of the paper is accepted, then the argument will not merely reshape our understanding of the brain, but what kinds of structures we expect to uncover in studying it. We cannot point to our hardware as limiting the shape and structure of our language in accordance to a set of universal rules. Nor can we succumb to the tempting conclusion of many otherwise strong philosophical arguments that grammatical structures cannot be learned through exposure to oral communication.