Language Emergence: Evidence From Nicaraguan Sign Language and Gestural Creation Paradigms

Abstract

While every human society has a language, no other animal has a communication system with this scope and complexity, and no other animal can acquire such a system as readily as we do. A central challenge for cognitive science is to discover where language comes from. What properties of human minds and communities allow for its creation? This dissertation takes two approaches to study this question. In the first paper, we use a gestural language creation paradigm to examine the source of a well-documented typological observation: the dominance of subject-initial word orders, SOV and SVO, across the world’s languages. When asked to gesture transitive events with an animate agent and inanimate patient, gesturers tend to produce SOV order, regardless of their native language, but when the patient is animate, gesturers shift to other orders, like SVO and OSV. Our results show that the observed avoidance of SOV is heavily driven by the animacy of the event participants, and that findings from gestural language paradigms are affected by specific constraints on how events are depicted in these short laboratory studies. The second paper examines the emergence of two types of temporal language in an emerging language, Nicaraguan Sign Language (NSL), comparing the linguistic devices for conveying temporal information among three age cohorts of signers. We find different patterns of development depending on the type of temporal information being expressed. The speed at which a language converges on devices for conveying information may depend on the abstractness of the representations. In the third paper, we explore recursion, defined as the application of a rule to its own output, in NSL. We looked at relative clauses, which pick out a member from a set. We find that while the grammatical form of relative clauses changes as the language develops, all signers produce sentences fulfilling the function of relative clauses. Our results suggest that different parts of language may arise at different times from different learning mechanisms, sources, and external pressures. Taken together, these papers illustrate how language emergence is a process of children’s minds interacting with each other over a few generations.