Speakers use more redundant referents with language learners: Evidence for communicatively-efficient referential choice

According to the communicative efficiency hypothesis, speakers should produce more linguistic material when comprehension difficulty increases. Here, we investigate a potential source of comprehension difficulty – listeners’ language proficiency – on speakers’ productions, using referential choice as a case study. On the one hand, the extent to which referential choice is impacted by the listener is debated. On the other hand, referential choice is impacted by communicative efficiency: pronouns are used less than longer referring expressions for less predictable referents (Tily & Piantadosi, 2009). Here, we compare participants’ descriptions of the same picture book to children, adult L2 learners and adult native speakers. We find that speakers use longer references when their interlocutors are learners – child and adult learners alike, illustrating an effect of listeners’ proficiency (regardless of age) on production choices. Importantly, the effect is stronger for child learners, pointing to possible differences between speech directed to child and adult learners. We discuss implications for theories of language change.