Three factors in language variation

Universal Grammar and statistical generalization from linguistic data have almost always been invoked as mutually exclusive means of explaining child language acquisition. This papers show that such segregation is both conceptually unnecessary and empirically flawed. We demonstrate the utility of general learning mechanisms in the acquisition of the core grammatical system through frequency effects in parameter setting, and develop an optimization-based model of productivity with applications to morphology and syntax in the periphery. These findings in child language support the approach to the evolution of language that seeks connections between language and other cognitive systems, in particular the consequence of general principles of efficient computation.