Disjunction has played a major role in advancing theories of logic, language, and cognition, featuring as the centerpiece of debates on the origins and development of logical thought. Recent studies have argued that due to non-adult-like pragmatic reasoning, preschool children’s comprehension of linguistic disjunction differs from adults in two ways. First, children are more likely to interpret “or” as “and” (conjunctive interpretations); Second, children are more likely to consider a disjunction as inclusive (lack of exclusivity implicatures). We tested adults and children’s comprehension of disjunction in existential sentences using two and three-alternative forced choice tasks, and analyzed children’s spontaneous verbal reactions prior to their forced-choice judgments. Overall our results are compatible with studies that suggest children understand the basic truth-conditional semantics of disjunction. Children did not interpret “or” as “and”, supporting studies that argue conjunctive interpretations are due to task demands. In addition, even though our forced-choice tasks suggest children interpreted disjunction as inclusive, spontaneous verbal reactions showed that children were sensitive to the adult-like pragmatics of disjunction. Theoretically, these studies provide evidence against previous developmental accounts, and lend themselves to two alternative hypotheses. First, that preschool children’s pragmatic knowledge is more adult-like than previously assumed, but forced-choice judgments are not sensitive enough to capture this knowledge. Second, children may have the knowledge of the relevant lexical scale themselves, but be uncertain whether a new speaker also has this knowledge (mutual knowledge of the scale).
The pervasive role of pragmatics in early language
