Interlocutor modelling in lexical alignment: The role of linguistic competence

In what is known as lexical alignment in dialogue, speakers tend to re-use their interlocutor’s prior lexical expressions, probably in an attempt to facilitate ease and success of comprehension for the interlocutor. But do speakers take into account their interlocutor’s linguistic competence when producing language to their interlocutor (e.g., using more lexical alignment towards an interlocutor with more limited linguistic competence to boost communicative success)? In three online experiments, we compared speakers’ tendency to lexically align with interlocutors of different linguistic competence: an adult native interlocutor, a child native interlocutor, and an adult non-native interlocutor. Native Mandarin-speaking participants were told that they would take turns with another participant (in fact just recordings) to name and match pictures on the internet. We compared lexical alignment with the three interlocutors in a between-participant design in Experiment 1 and later, in a within-participant design, lexical alignment with child vs. adult native interlocutors in Experiment 2 and lexical alignment with adult non-native vs. native interlocutors in Experiment 3. Speakers more often re-used picture names previously produced by a child than adult native interlocutor, and by an adult non-native than native interlocutor. These interlocutor-dependent effects in lexical alignment were not due to memory strength or speech rate associated with an interlocutor’s utterances; instead, these findings suggest that speakers model their interlocutor’s linguistic competence and lexically align more with linguistically less competent interlocutors in order to maximize communicative success.