Testing theories of SDA via acquisition

Abstract

The aim of this study is to examine how children and adults interpret indicative and counterfactual conditionals with disjunctive antecedents, such as “if A or B, C”. Disjunctive antecedent conditionals (DACs) are associated with a debated inference known as the simplification of disjunctive antecedents (SDA), where a DAC is interpreted as equivalent to the conjunction of its simplifications: “if A, C” and “if B, C”. To explore this, we administered a picture-supported Truth Value Judgment Task to 140 children (aged 5;0–9;11) and 28 adults. Participants were asked to evaluate the truth or falsity of 16 DACs in both indicative and counterfactual mode, with position effects controlled (e.g., testing both “if A or B” and “if B or A”). Our results reveal that the SDA interpretation emerges as early as age 5. Moreover, a growing preference for the SDA interpretation is associated with a decreasing tendency to adopt an alternative interpretation, in which a DAC is analyzed as the disjunction of the two simplifications.