Interaction Studies - Volume 18, Issue 3, 2017

Following a synthesis of naturalistic and experimental studies of language creation, we propose a theoretical model that describes the process through which human communication systems might arise and evolve. Three key processes are proposed that give rise to effective, efficient and shared human communication systems: (1) motivated signs that directly resemble their meaning facilitate cognitive alignment, improving communication success; (2) behavioral alignment onto an inventory of shared sign-to-meaning mappings bolsters cognitive alignment between interacting partners; (3) sign refinement, through interactive feedback, enhances the efficiency of the evolving communication system. By integrating the findings across a range of diverse studies, we propose a theoretical model of the process through which the earliest human communication systems might have arisen and evolved. Importantly, because our model is not bound to a single modality it can describe the creation of shared sign systems across a range of contexts, informing theories of language creation and evolution.

In language evolution research, the use of computational and experimental methods to investigate the emergence of structure in language is exploding. In this review, we look exclusively at work exploring the emergence of structure in speech, on both a categorical level (what drives the emergence of an inventory of individual speech sounds), and a combinatorial level (how these individual speech sounds emerge and are reused as part of larger structures). We show that computational and experimental methods for investigating population-level processes can be effectively used to explore and measure the effects of learning, communication and transmission on the emergence of structure in speech. We also look at work on child language acquisition as a tool for generating and validating hypotheses for the emergence of speech categories. Further, we review the effects of noise, iconicity and production effects.

Arbitrary communication systems can emerge from iconic beginnings through processes of conventionalisation via interaction. Here, we explore whether this process of conventionalisation occurs with continuous, auditory signals. We conducted an artificial signalling experiment. Participants either created signals for themselves, or for a partner in a communication game. We found no evidence that the speech-like signals in our experiment became less iconic or simpler through interaction. We hypothesise that the reason for our results is that when it is difficult to be iconic initially because of the constraints of the modality, then iconicity needs to emerge to enable grounding before conventionalisation can occur. Further, pressures for discrimination, caused by the expanding meaning space in our study, may cause more complexity to emerge, again as a result of the restrictive signalling modality. Our findings have possible implications for the processes of conventionalisation possible in signed and spoken languages, as the spoken modality is more restrictive than the manual modality.

Gesture-first theories of language origins often raise two unsubstantiated arguments against vocal origins. First, they argue that great ape vocal behavior is highly constrained, limited to a fixed, species-typical repertoire of reflexive calls. Second, they argue that vocalizations lack any significant potential to ground meaning through iconicity, or resemblance between form and meaning. This paper reviews the considerable evidence that debunks these two “myths”. Accumulating evidence shows that the great apes exercise voluntary control over their vocal behavior, including their breathing apparatus, larynx, and supralaryngeal articulators. They are also able to learn new vocal behaviors, and even show some rudimentary ability for vocal imitation. In addition, an abundance of research demonstrates that the vocal modality affords rich potential for iconicity. People can understand iconicity in sound symbolism, and they can produce iconic vocalizations to communicate a diverse range of meanings. Thus, two of the primary arguments against vocal origins theories are not tenable. As an alternative, the paper concludes that the origins of language – going as far back as our last common ancestor with great apes – are rooted in iconicity in both gesture and vocalization.

This paper outlines a first attempt to model the special constraints that arise in language processing in conversation, and to explore the implications such functional considerations may have on language typology and language change. In particular, we focus on processing pressures imposed by conversational turn-taking and their consequences for the cultural evolution of the structural properties of language. We present an agent-based model of cultural evolution where agents take turns at talk in conversation. When the start of planning for the next turn is constrained by the position of the verb, the stable distribution of dominant word orders across languages evolves to match the actual distribution reasonably well. We suggest that the interface of cognition and interaction should be a more central part of the story of language evolution.

Some spoken words are iconic, exhibiting a resemblance between form and meaning. We used native speaker ratings to assess the iconicity of 3001 English words, analyzing their iconicity in relation to part-of-speech differences and differences between the sensory domain they relate to (sight, sound, touch, taste and smell). First, we replicated previous findings showing that onomatopoeia and interjections were highest in iconicity, followed by verbs and adjectives, and then nouns and grammatical words. We further show that words with meanings related to the senses are more iconic than words with abstract meanings. Moreover, iconicity is not distributed equally across sensory modalities: Auditory and tactile words tend to be more iconic than words denoting concepts related to taste, smell and sight. Last, we examined the relationship between iconicity (resemblance between form and meaning) and systematicity (statistical regularity between form and meaning). We find that iconicity in English words is more strongly related to sensory meanings than systematicity. Altogether, our results shed light on the extent and distribution of iconicity in modern English.

A persistent controversy in language evolution research has been whether language emerged in the gestural-visual or in the vocal-auditory modality. A “dialectic” solution to this age-old debate has now been gaining ground: language was fully multimodal from the start and remains so to this day. In this paper, we show this solution to be too simplistic and outline a more specific theoretical proposal, which we designate as pantomime-first. To decide between the multimodal-first and pantomime-first alternatives, we review several lines of interdisciplinary evidence and complement it with a cognitive-semiotic experiment. In the study, the participants saw – and then matched to hand-drawn images – recordings of short transitive events enacted by 4 actors in two conditions: visual (only body movement) and multimodal (body movement accompanied by nonlinguistic vocalization). Significantly, the matching accuracy was greater in the visual than the multimodal condition, though a follow-up experiment revealed that the emotional profiles of the events enacted in the multimodal condition could be reliably detected from the sound alone. We see these results as supporting the proposed pantomime-first scenario.