Stephen Crain (Macquarie University) - Language Universals and Universal Grammar
When logical connectives (disjunction/conjunction) appear in negative statements, the combination often yields a scope ambiguity, i.e., both surface scope and inverse scope readings. Interestingly, adult speakers of different languages exhibit different scope preferences. For example, adult speakers of English prefer the surface scope reading of negated disjunctions, whereas adult speakers of Japanese prefer the inverse scope reading of negated disjunctions. Despite these cross-linguistic differences for adult speakers, children acquiring even typologically distinct languages initially adopt the same scope assignments when the truth conditions corresponding to the alternative interpretations stand in a subset/superset relation. In such cases, children's initial interpretation is based on principles of language learnability, and not on ease of processing. In another class of sentence structures, scope ambiguities do not arise at all, namely when one of the logical expressions is introduced covertly. When scope ambiguities are canceled in these linguistic structures, children and adults assign the same interpretations across languages. For these structures, the interpretation that is assigned is based on the (partly hidden) surface syntax, rather than on principles of language learnability. So language universals involving covert logical expressions are not the same as children's initial scope assignments. The conclusion: Universal Grammar cannot be conflated with language universals.