The Comprehension of Conjunction and Disjunction by Toddlers

Research on the acquisition of language's logical connectives has generally focused on production studies (spontaneous or elicited). According to such data, parts of the logical vocabulary - in particular, conjunction and disjunction - are acquired relatively late, with adult-like production evident from age 3 for conjunction and from age 6 for disjunction. In this study, we employed the intermodal preferential looking paradigm to target the comprehension abilities of Italian-speaking toddlers of an average age of 28 months, a younger cohort than in previous studies. We collected eye-fixation data as toddlers inspected two images whilst listening to conjunctive and disjunctive sentences and analysed these data with a generalised additive model, obtaining a sequential record of the online, implicit processing of the sentences. The results indicate that toddlers discriminate between conjunction and disjunction and favour an inclusive reading of disjunction, furthermore providing evidence for the earliest comprehension of the logical connectives in ontogeny.