Sorry, you make less sense to me: The effect of non-native speaker status on metaphor processing

Preconceived assumptions about the speaker have been shown to strongly and automatically influence speech interpretation. This study contributes to previous research by investigating the impact of non-nativeness on perceived metaphor sensibility. To eliminate the effects of speech disfluency, we used exclusively written sentences but introduced their "authors" as having a strong native or non-native accent through a written vignette. The author's language proficiency was never mentioned. Metaphorical sentences featured familiar ("The pictures streamed through her head") and unfamiliar ("The textbooks snored on the desk") verbal metaphors and closely matched literal expressions from a pre-tested database. We also administered a battery of psychological tests to assess whether ratings could be predicted by individual differences. The results revealed that all sentences attributed to the non-native speaker were perceived as less sensical. Incorporating the identity of the non-native speaker also took more effort, as indicated by longer processing and evaluation times. Additionally, while a general bias against non-native speakers emerged even without oral speech, person-based factors played a significant role. Lower ratings of non-native compared to native speakers were largely driven by individuals from less linguistically diverse backgrounds and those with less cognitive reflection. Extraversion and political ideology also modulated ratings in a unique way. The study highlights the impact of preconceived notions about the speaker on sentence processing and the importance of taking interpersonal variation into account.