Asymmetric accommodation during interaction leads to the regularisation of linguistic variants

Linguistic variation is constrained by grammatical and social context, making the occurrence of particular variants at least somewhat predictable. We explore accommodation during interaction as a potential mechanism to explain this phenomenon. Specifically, we test a hypothesis derived from historical linguistics that interaction between categorical and variable users is inherently asymmetric: while variable users accommodate to their partners, categorical users are reluctant to do so, because it would mean violating the rules of their grammar. We ran two experiments in which participants learnt a miniature language featuring a variable or categorical grammatical marker and then used it to communicate. Our results support the asymmetric accommodation hypothesis: variably-trained participants accommodated to their categorically-trained partners, who tended not to change their behaviour during interaction. These results may reflect general social cognitive constraints on acquiring and using variable linguistic devices, and give insights into how small-scale interactive mechanisms may influence population-level linguistic phenomena.