Authors: W Garrett Mitchener
Publish Date: 2007/01/30
Volume: 69, Issue: 3, Pages: 1093-1118
Abstract
We investigate a model of language evolution based on population game dynamics with learning First we examine the case of two genetic variants of universal grammar UG the heart of the human language faculty assuming each admits two possible grammars The dynamics are driven by a communication game We prove using dynamical systems techniques that if the payoff matrix obeys certain constraints then the two UGs are stable against invasion by each other that is they are evolutionarily stable Then we prove a similar theorem for an arbitrary number of disjoint UGs In both theorems the constraints are independent of the learning process Intuitively if a mutation in UG results in grammars that are incompatible with the established languages then the mutation will die out because mutants will be unable to communicate and therefore unable to realize any potential benefit of the mutation An example for which these theorems do not apply shows that compatible mutations may or may not be able to invade depending on the populations history and the learning process These results suggest that the genetic history of language is constrained by the need for compatibility and that mutations in the language faculty may have died out or taken over due more to historical accident than to any straightforward notion of relative fitness
Keywords: