Language as Shaped by the Brain

The study of human language has frequently treated questions concerning the evolution, acquisition and processing of language as being independent of each other. However, this tendency is misguided: there are important constraints between each of these areas that allow them to shed light on one another. I start the first lecture by outlining an integrated framework within which to understand language across multiple time-scales. Focusing then on the issue of language evolution, I argue that traditional notions of universal grammar as a biological endowment of abstract linguistic constraints can be ruled out on evolutionary grounds. Instead, the fit between the mechanisms employed for language and the way in which language is acquired and used can be explained by processes of cultural evolution shaped by the human brain. On this account, language evolved by 'piggy-backing' on pre-existing neural mechanisms, constrained by socio-pragmatic considerations, the nature of our thought processes, perceptuo-motor factors, and cognitive limitations on learning, memory and processing. Using behavioral, computational and molecular genetics methods, I then explore how one of these constraints—the ability to learn and process sequentially presented information—may have played an important role in shaping language through cultural evolution. I conclude that most of the constraints that have shaped language evolution still affect our current use language, suggesting that language universals may be best viewed as probabilistic tendencies resulting from multiple-constraint satisfaction.