Why Island Constraint Is Weaker in Japanese than in English: A Processing Perspective

The constraints on discontinuous dependency in a sentence have been discussed as “island constraint”. Island phenomenon can be observed in many languages; however, while the island effect is quite noticeable in English, it seems obscure in Japanese. This study thus experimentally evaluates the strength of island effect in Japanese complex sentences quantitatively and demonstrates that the island effect in Japanese is weaker than that in English. Furthermore, we attempt to attribute the difference in the strength of the island effect in these two languages to their processing characteristics; that is, the syntactic relationship between two discontinuous elements in English must be computed at the head of an island, with one of the two elements unreceived, while the syntactic computation at the head of an island in Japanese is performed with both elements received. We assume that the processing of discontinuous dependency is thus more costly in English than in Japanese, and that the strong island effect in English reflects the relative difficulty of the syntactic computation. We obtained evidence for our hypothesis from an experiment asking participants to make grammatical judgments on Japanese sentences in which we manipulated their word-order in three ways. We suggest that part of the apparent syntactic phenomenon can be attributed to processing factors.