Speaker: Masoud Jasbi (Harvard)
Title: Nativism vs. Constructivism: The Case of Disjunction
Time: Friday, November 22th, 2pm – 3pm
Location: 32-D461
Abstract: Disjunction has been a major source of insight for theories of meaning and language acquisition. Both nativist and constructivist theories have claimed that children’s development of disjunction conforms to their predictions. What are nativist and constructivist accounts of disjunction acquisition? How often do children hear disjunction in their parents’ speech? in what contexts? What type of learning model can succeed in learning the interpretations of disjunction from child-directed speech? In this talk, I review previous theories of disjunction acquisition and present the results of a study on naturalistic recordings of parent-child interactions. The results suggest that children may learn to interpret a disjunction by partitioning their form-meaning mappings based on salient cues that accompany a disjunction in child-directed speech. In order to better understand the distribution of “or” in parents’ and children’s speech, I collected statistics of its use across speakers, ages, and contexts. The results show that children start producing “or” between 18-30 months and by 42 months their productions plateau at a constant rate. I also show that the most likely interpretation of “or” in child-directed speech is exclusive disjunction. However, exclusive interpretations correlated with a rise-fall intonation, and logically inconsistent propositions. In the absence of these two cues, “or” was commonly not exclusive. Our computational modeling suggests that a hypothetical learner can successfully interpret an English disjunction by mapping forms to meanings after partitioning the input using the set of salient cues in the context of the utterance. I discuss the implications of this work for current theories of word learning and language acquisition.