Abstract

Human language arises from biological evolution, individual learning, and cultural transmission, but the interaction of these three processes  has  not  been  widely  studied.  We  set  out  a  formal framework for analyzing cultural transmission, which allows us to investigate how innate learning biases are related to universal properties of language. We show that cultural transmission can magnify weak biases into strong linguistic universals, undermining one of the arguments for strong innate constraints on language learning. As a consequence, the strength of innate biases can be shielded  from  natural  selection,  allowing  these  genes  to  drift. Furthermore,  even  when  there  is  no  natural selection,  cultural transmission can produce apparent adaptations. Cultural transmission thus provides an alternative to traditional nativist and adaptationist explanations for the properties of human languages.