In a sentence like “The bear disturbed the lion because it was aggressive”, known as a Winograd schema (Winograd, 1972; Levesque, 2017), the pronoun “it” is usually interpreted as referring to the bear (NP1) and not to the lion (NP2). This interpretation is on the one hand based on the meaning of the interpersonal verb in the main clause, which offers an implicit causality bias of who the cause of the action is and thus to whom the pronoun refers. On the other hand, the interpretation is affected by the adjective that appears at the end of the sentence. We investigated how the pairing of specific verbs and adjectives modulates the interpretation of pronoun reference.
We presented sentences including verbs biasing NP1 or NP2 (see Ferstl et al., 2011). We picked adjectives which presumably are more compatible with pronoun reference to NP1 (first example) or NP2 (e.g., “The bear disturbed the lion because it was exhausted”). Subsequently, a second sentence paired one of the two NPs with the adjective (e.g., “The bear was exhausted” vs. "The lion was exhausted”). Participants judged the coherence of the two sentences.
Judgement revealed a strong verb bias replicating the results of Ferstl et al. (2011) for German verbs. Moreover, incompatible verb-adjective pairs were judged to be less coherent than compatible verb-adjective pairs. The results show that verb bias and adjective meaning together provide meaningful cues for resolving ambiguous pronoun reference.