A Noisy-Channel Account of Crosslinguistic Word-Order Variation

TLDR

Word order varies across languages, with SVO and SOV being most common, and recent evidence suggests SOV may be the default order. The study asks why SVO order is so prevalent despite the SOV default. The authors propose a noisy‑channel account in which sensitivity to potential noise causes a shift from default SOV to SVO for semantically reversible events that would otherwise be ambiguous. Experiments with gesture production in English, Japanese, and Korean confirm this prediction, and the hypothesis also explains other cross‑linguistic patterns such as the distribution of case marking.

Abstract

The distribution of word orders across languages is highly nonuniform, with subject-verb-object (SVO) and subject-object-verb (SOV) orders being prevalent. Recent work suggests that the SOV order may be the default in human language. Why, then, is SVO order so common? We hypothesize that SOV/SVO variation can be explained by language users’ sensitivity to the possibility of noise corrupting the linguistic signal. In particular, the noisy-channel hypothesis predicts a shift from the default SOV order to SVO order for semantically reversible events, for which potential ambiguity arises in SOV order because two plausible agents appear on the same side of the verb. We found support for this prediction in three languages (English, Japanese, and Korean) by using a gesture-production task, which reflects word-order preferences largely independent of native language. Other patterns of crosslinguistic variation (e.g., the prevalence of case marking in SOV languages and its relative absence in SVO languages) also straightforwardly follow from the noisy-channel hypothesis.