In this paper, we use motion tracking technology to document the birth of a brand new language: Nicaraguan Sign Language. Languages are dynamic entities that undergo change and growth through use, transmission, and learning, but the earliest stages of this process are generally difficult to observe as most languages have been used and passed down for many generations. Here, we observe a rare case of language emergence: the earliest stages of the new sign language in Nicaragua. By comparing the signing (...) of the oldest and youngest signers of Nicaraguan Sign Language, we can track how the language itself is changing. Using motion tracking technology, we document a decrease in the size of articulatory space of Nicaraguan Sign Language signers over time. The reduction in articulatory space in Nicaraguan Sign appears to be the joint product of several decades of use and repeated transmission of this new language. (shrink)

Homesign is a visual–gestural form of communication that emerges between deaf individuals and their hearing interlocutors in the absence of a conventional sign language. I argue here that homesign conversations form a perfect testcase to study the extent to which pragmatic competence is foundational rather than derived from our linguistic abilities.

Human expression is open-ended, versatile, and diverse, ranging from ordinary language use to painting, from exaggerated displays of affection to micro-movements that aid coordination. Here we present and defend the claim that this expressive diversity is united by an interrelated suite of cognitive capacities, the evolved functions of which are the expression and recognition of informative intentions. We describe how evolutionary dynamics normally leash communication to narrow domains of statistical mutual benefit, and how expression is unleashed in humans. The relevant (...) cognitive capacities are cognitive adaptations to living in a partner choice social ecology; and they are, correspondingly, part of the ordinarily developing human cognitive phenotype, emerging early and reliably in ontogeny. In other words, we identify distinctive features of our species' social ecology to explain how and why humans, and only humans, evolved the cognitive capacities that, in turn, lead to massive diversity and open-endedness in means and modes of expression. Language use is but one of these modes of expression, albeit one of manifestly high importance. We make cross-species comparisons, describe how the relevant cognitive capacities can evolve in a gradual manner, and survey how unleashed expression facilitates not only language use, but also novel behaviour in many other domains too, focusing on the examples of joint action, teaching, punishment, and art, all of which are ubiquitous in human societies but relatively rare in other species. Much of this diversity derives from graded aspects of human expression, which can be used to satisfy informative intentions in creative and new ways. We aim to help reorient cognitive pragmatics, as a phenomenon that is not a supplement to linguistic communication and on the periphery of language science, but rather the foundation of the many of the most distinctive features of human behaviour, society, and culture. (shrink)

Gestural and pantomimic accounts of language origins propose that language did not develop directly from ape vocalisations, but rather that its emergence was preceded by an intervening stage of bodily-visual communication, during which our ancestors communicated with their hands, arms, and the entire body. Gestural and pantomimic scenarios are again becoming popular in language evolution research, but this line of thought has a long and interesting history that gained special prominence in the Enlightenment, often considered the golden age of glottogony. (...) We highlight several themes key to this line of reflection, such as the idea of innate communication that consists of visual bodily signs and non-linguistic vocalisations; the division of labour between these two semiotic resources ; or the developmental trajectory of this bi-modal system of communication determined by its transmission through generations of users and the intervention of social factors. We confront these ideas with problems discussed in current language evolution research, focusing on polysemioticity, sign function, conventionality and modality transition. (shrink)

Cognitive Science, Volume 46, Issue 5, May 2022.

Several lines of research within developmental psychology, experimental semiotics and language origins studies have recently converged in their interest in pantomime as a system of bodily communication distinct from both language (spoken or signed) and nonlinguistic gesticulation. These approaches underscore the effectiveness of pantomime, which despite lack of semiotic conventions is capable of communicating complex meanings. However, very little research is available on the structural underpinnings of this effectiveness, that is, the specific properties of pantomime that determine its communicative success. (...) To help fill in this gap, we conducted an exploratory rating study aimed at identifying those properties of pantomime that facilitate its understanding. We analysed an existing corpus of 602 recordings of whole-body re-enactments of short transitive events, coding each of them for 6 properties, and found out that the presence of salient elements (conspicuous objects in a specific semantic space), image mapping (representing the physical orientation of the object), and gender markers (distinguishing between the represented characters) increased the guessability of pantomimes. (shrink)

Silent gestures consist of complex multi‐articulatory movements but are now primarily studied through categorical coding of the referential gesture content. The relation of categorical linguistic content with continuous kinematics is therefore poorly understood. Here, we reanalyzed the video data from a gestural evolution experiment (Motamedi, Schouwstra, Smith, Culbertson, & Kirby, 2019), which showed increases in the systematicity of gesture content over time. We applied computer vision techniques to quantify the kinematics of the original data. Our kinematic analyses demonstrated that gestures (...) become more efficient and less complex in their kinematics over generations of learners. We further detect the systematicity of gesture form on the level of thegesture kinematic interrelations, which directly scales with the systematicity obtained on semantic coding of the gestures. Thus, from continuous kinematics alone, we can tap into linguistic aspects that were previously only approachable through categorical coding of meaning. Finally, going beyond issues of systematicity, we show how unique gesture kinematic dialects emerged over generations as isolated chains of participants gradually diverged over iterations from other chains. We, thereby, conclude that gestures can come to embody the linguistic system at the level of interrelationships between communicative tokens, which should calibrate our theories about form and linguistic content. (shrink)

Cognitive Science, Volume 46, Issue 10, October 2022.

In this study, we aim to disentangle pantomime from early signs in a newly-born sign language: Sao Tome and Principe Sign Language. Our results show that within 2 years of their first contact with one another, a community of 100 participants interacting everyday was able to build a shared language. The growth of linguistic systematicity, which included a decrease in use of pantomime, reduction of the amplitude of signs and an increase in articulation economy, showcases a learning, and social interaction (...) process that constitutes a continuum and not a cut-off system. The human cognitive system is endowed with mechanisms for symbolization that allow the process of arbitrariness to unfold and the expansion of linguistic complexity. Our study helps to clarify the role of pantomime in a new sign language and how this role might be linked with language itself, showing implications for language evolution research. (shrink)

When interlocutors repeatedly describe referents to each other, they rapidly converge on referring expressions which become increasingly systematized and abstract as the interaction progresses. Previous experimental research suggests that interactive repair mechanisms in dialogue underpin convergence. However, this research has so far only focused on the role of other-initiated repair and has not examined whether self-initiated repair might also play a role. To investigate this question, we report the results from a computer-mediated maze task experiment. In this task, participants communicate (...) with each other via an experimental chat tool, which selectively transforms participants’ private turn-revisions into public self-repairs that are made visible to the other participant. For example, if a participant, A, types “On the top square,” and then before sending, A revises the turn to “On the top row,” the server automatically detects the revision and transforms the private turn-revisions into a public self-repair, for example, “On the top square umm I meant row.” Participants who received these transformed turns used more abstract and systematized referring expressions, but performed worse at the task. We argue that this is due to the artificial self-repairs causing participants to put more effort into diagnosing and resolving the referential coordination problems they face in the task, yielding better grounded spatial semantics and consequently increased use of abstract referring expressions. (shrink)

Cognitive Science, Volume 45, Issue 11, November 2021.

Experimental Semiotics (ES) is the study of novel forms of communication that communicators develop in laboratory tasks whose designs prevent them from using language. Thus, ES relates to pragmatics in a “pure,” radical sense, capturing the process of creating the relation between signs and their interpreters as biological, psychological, and social agents. Since such a creation of meaning-making from scratch is of central importance to language evolution research, ES has become the most prolific experimental approach in this field of research. (...) In our paper, we report the results of a study on the scope of recent ES and evaluate the ways in which it is relevant to the study of language origins. We coded for multiple levels across 13 dimensions related to the properties of the emergent communication systems or properties of the study designs, such as type of goal (coordination versus referential), modality of communication, absence or presence of turn-taking, or the presence of vertical vs. horizontal transmission. We discuss our findings and our classification, focusing on the advantages and limitations of those trends in ES, and in particular their ecological validity in the context of bootstrapping communication and the evolution of language. (shrink)

Silent gesture is not considered to be linguistic, on par with spoken and sign languages. It is claimed that silent gestures, unlike language, represent events holistically, without compositional structure. However, recent research has demonstrated that gesturers use consistent strategies when representing objects and events, and that there are behavioral and clinically relevant limits on what form a gesture may take to effect a particular meaning. This systematicity challenges a holistic interpretation of silent gesture, which predicts that there should be no (...) stable form‐meaning correspondence across event representations. Here, we demonstrate to the contrary that untrained gesturers systematically manipulate the form of their gestures when representing events with and without a theme (e.g., Someone popped the balloon vs. Someone walked), that is, transitive and intransitive events. We elicited silent gestures and annotated them for manual features active in coding transitivity distinctions in sign languages. We trained linear support vector machines to make item‐by‐item transitivity predictions based on these features. Prediction accuracy was good across the entire dataset, thus demonstrating that systematicity in silent gesture can be explained with recourse to subunits. We argue that handshape features are constructs co‐opted from cognitive systems subserving manual action production and comprehension for communicative purposes, which may integrate into the linguistic system of emerging sign languages. We further suggest that nonsigners tend to map event participants to each hand, a strategy found across genetically and geographically distinct sign languages, suggesting the strategy's cognitive foundation. (shrink)