Priming and unidirectional language change

Abstract In this paper we argue that the psycholinguistic mechanism of priming may account for the empirical observation that grammaticalization processes typically proceed in one direction only. It is shown how two well-known unidirectional changes, i.e. the development from spatial to temporal expressions and phonological reduction, may be connected to cases of asymmetric priming as reported in the psycholinguistic literature. In these cases a form or concept A primes a form or concept B, but not vice versa , and this cognitive asymmetry corresponds precisely to the observed unidirectional pathway from A to B in diachronic change. Ultimately, then, we argue that what appears as diachronic trajectories of unidirectional change is decomposable into atomic steps of asymmetric priming in language use. More generally, we also suggest that priming is the ‘missing link’ in evolutionary models of language change in that it provides for a plausible linguistic replicating mechanism, i.e. an ‘amplifier’ of linguistic units. This is a programmatic paper which should bring to attention the potential of fruitfully applying insights from psycholinguistic research to some central issues of historical linguistics. Specifically, our approach allows for the formulation of falsifiable predictions that can be tested with present-day speakers, under the uniformitarian assumption that the same cognitive mechanisms that we find to be operating in present-day speakers also have operated in past speakers of a language.