Selective imitation for a private sign system

A distinctive feature of all human languages is the diverse and arbitrary n ature of the sign (signifier). This can be interpreted as stating that the mapping between signals and referents is established by convention rather t han by functional constraints. This property of the sign provides for a gre at deal of linguistic flexibility and is a key component of symbolic commun ication. Game theoretic models to describe signal imitation are investigate d with a view to understanding how non-arbitrary (indexical) animal-style s ignals might 'evolve' culturally into diverse, arbitrary signs. I explore t he evolutionary hypothesis that private, arbitrary signs emerge as a result of selective imitation within a socially structured population. Once arbit rary signs have emerged, they contribute towards greater assortative intera ctions among individuals using a shared sign system. In natural populations , the models for imitation will very often be close kin. Hence, kinship pro vides one mechanism for the creation of true symbols. An imitation-structur ed population can support many more sign systems than an equivalent non-str uctured population and is one in which symbols become the dominant force in assortative interactions. (C) 2001 Academic Press.