The evolutionary language game

We explore how evolutionary game dynamics have to be modified to accomodate a mathematical framework for the evolution of language. In particular, we are interested in the evolution of vocabulary, that is associations between signals and objects. We assume that successful communication contributes t o biological fitness: individuals who communicate well leave more offspring . Children inherit from their parents a strategy for language learning (a l anguage acquisition device). We consider three mechanisms whereby language is passed from one generation to the next: (i) parental learning: children learn the language of their parents; (ii) role model learning: children lea rn the language of individuals with a high payoff; and (iii) random learnin g: children learn the language of randomly chosen individuals. We show that parental and role model learning outperform random learning. Then we intro duce mistakes in language learning; and study how this process changes lang uage over time. Mistakes increase the overall efficacy of parental and role model learning: in a world with errors evolutionary adaptation is more eff icient. Our model also provides a simple explanation why homonomy is common while synonymy is rare. (C) 1999 Academic Press.