Variation in Linguistic Complexity and its Cognitive Underpinning

Linguistic complexity – manifested in terms of hierarchical recursive structures generated by grammar – is often discussed from the perspective of cross-linguistic comparison (cf. Everett, 2005; Nevins, Pesetsky, & Rodrigues, 2009 on Pirahã). In this paper, we focus instead on the variation in complexity within a single language, English, and on the lower bound of complexity, specifically (cf. Futrell et al., 2016). We report results of two studies, a corpus study (Study 1) and a production experiment (Study 2), that investigate syntactic complexity of expressions that arise in the context of human-computer interaction and compare them to the standard language. The results of both studies show that the expressions generated in the context of human-computer interaction exhibit lesser structural complexity and often violate the norm of the language (cf. margaret mead culture famous research). Our results suggest that such expressions are generated by a qualitatively different type of formal grammar, Linear Grammar (Jackendoff & Wittenberg, 2017), rather than by recursive grammar (Roeper, 1999).