Potentially recursive structures emerge quickly when a new language community forms.

Human languages can express an infinite number of thoughts despite having a finite set of words and rules. This is due, in part, to recursive structures, which allow us to embed one instance of a rule inside another. We investigated the origins of recursion by studying the development of Nicaraguan Sign Language (LSN), which emerged in the last 40 years and is not derived from any existing language.

Lexical Iconicity is differentially favored under transmission in a new sign language: The effect of type of iconicity.

Observations that iconicity diminishes over time in sign languages pose a puzzle--why should something so evidently useful and functional decrease? Using an archival dataset of signs elicited over 15 years from 4 first-cohort and 4 third-cohort signers of an emerging sign language (Nicaraguan Sign Language), we investigated changes in pantomimic (body-to-body) and perceptual (body-to-object) iconicity. We make three key observations: (1) there is greater variability in the signs produced by the first cohort compared to the third; (2) while both types of iconicity are evident, pantomimic iconicity is more prevalent than perceptual iconicity for both groups; and (3) across cohorts, pantomimic elements are dropped to a greater proportion than perceptual elements. The higher rate of pantomimic iconicity in the first-cohort lexicon reflects the usefulness of body-as-body mapping in language creation.

Structural cues for symmetry, asymmetry, and non-symmetry in Central Taurus Sign Language.

We investigate how predicates expressing symmetry, asymmetry and non-symmetry are encoded in a newly emerging sign language, Central Taurus Sign Language (CTSL). We find that predicates involving symmetry (i.e.

The communicative importance of agent-backgrounding: Evidence from homesign and Nicaraguan Sign Language.

Some concepts are more essential for human communication than others. In this paper, we investigate whether the concept of agent-backgrounding is sufficiently important for communication that linguistic structures for encoding this concept are present in young sign languages. Agent-backgrounding constructions serve to reduce the prominence of the agent - the English passive sentence a book was knocked over is an example.

The emergence of the formal category "symmetry" in a new sign language.

Logical properties such as negation, implication, and symmetry, despite the fact that they are foundational and threaded through the vocabulary and syntax of known natural languages, pose a special problem for language learning. Their meanings are much harder to identify and isolate in the child's everyday interaction with referents in the world than concrete things (like spoons and horses) and happenings and acts (like running and jumping) that are much more easily identified, and thus more easily linked to their linguistic labels (, , , ). Here we concentrate attention on the category of symmetry [a relation is symmetrical if and only if (iff) for all , : if (,), then (,)], expressed in English by such terms as , , , and After a brief introduction to how symmetry is expressed in English and other well-studied languages, we discuss the appearance and maturation of this category in Nicaraguan Sign Language (NSL).