Multimodal communication and language origins: integrating gestures and vocalizations

Abstract

The presence of divergent and independent research traditions in the gestural and vocal domains of primate communication has resulted in major discrepancies in the definition and operationalization of cognitive concepts. However, in recent years, accumulating evidence from behavioural and neurobiological research has shown that both human and non‐human primate communication is inherently multimodal. It is therefore timely to integrate the study of gestural and vocal communication. Herein, we review evidence demonstrating that there is no clear difference between primate gestures and vocalizations in the extent to which they show evidence for the presence of key language properties: intentionality, reference, iconicity and turn‐taking. We also find high overlap in the neurobiological mechanisms producing primate gestures and vocalizations, as well as in ontogenetic flexibility. These findings confirm that human language had multimodal origins. Nonetheless, we note that in great apes, gestures seem to fulfil a carrying (i.e. predominantly informative) role in close‐range communication, whereas the opposite holds for face‐to‐face interactions of humans. This suggests an evolutionary shift in the carrying role from the gestural to the vocal stream, and we explore this transition in the carrying modality. Finally, we suggest that future studies should focus on the links between complex communication, sociality and cooperative tendency to strengthen the study of language origins.

The origins of gestures and language: history, current advances and proposed theories

“…It is now clear that human and non‐human primate communication systems are multimodal (at both the behavioural and neural levels) and that interactions between modes of communication are important: vocalisations necessarily imply oro‐facial expressions, and gestures can be associated with vocalisations, oro‐facial expressions and/or eye behaviours, and vice versa (e.g. Arbib et al ., ; Masataka, ; Lemasson, ; Ghazanfar et al ., ; Slocombe, Waller & Liebal, ; Taglialatela et al ., ; Ghazanfar, ; Scharff, Friederici & Petrides, ; Gillespie‐Lynch et al ., ; Liebal et al ., ; Vigliocco, Perniss & Vinson, ; Meguerditchian & Vauclair, ; Levinson & Holler, ; Fröhlich et al ., ; Fig. ).…”

“…Such findings have led a growing number of researchers to favour the alternative multimodal theory of language origins: the multimodal, rhythmic and social‐interactive nature of human language would be the result, at least partly, of the coevolution of gestural, vocal, oro‐facial and eye signalling (e.g. Arbib et al ., ; Masataka, ; Lemasson, ; Slocombe, Waller & Liebal, ; Taglialatela et al ., ; Ghazanfar, ; Gillespie‐Lynch et al ., ; Levinson & Holler, ; Liebal et al ., ; Meguerditchian & Vauclair, ; Fröhlich et al ., ). This is in agreement with data for humans (e.g.…”

Multimodal pair‐bond maintenance: A review of signaling across modalities in pair‐bonded nonhuman primates

“…While researchers have begun to simultaneously investigate the use of tactile, acoustic, chemical, and visual signals, this research has largely focused on the great apes (Fröhlich & van Schaik, 2018;Fröhlich, Sievers, Townsend, Gruber, & van Schaik, 2019;Leavens & Hopkins, 2005;Leavens, Russell, & Hopkins, 2010;Taglialatela et al, 2015;Taglialatela, Russell, Schaeffer, & Hopkins, 2011;Wilke et al, 2017) (Kleiman, 1977; but see higher rates in dispersed pairs, e.g., red-tailed sportive lemurs, Lepilemur ruficaudatus; Hilgartner, Fitchel, Kappeler, & Zinner, 2012), pair-mates frequently exhibit strongly correlated behavioral responses to extra-pair strangers, including increased spatial cohesion and physical proximity between pair-mates, as well as coordinated expression of agonistic displays, including visual, tactile, chemical, and auditory components (as in C. moloch, Anzenberger, Mendoza, & Mason, 1986;C. cupreus, Carp et al, 2016).…”

Understanding Language Evolution: Beyond Pan‐Centrism

“…Findings regarding gestural communication in great apes, including inter-species comparisons, evoke a similar general interpretation. [94][95][96] Altogether, the burgeoning strand of great ape vocal research [28,91,97] shows that traditional ideas about what great apes can and (mostly) cannot do are outdated, too crude or unsubstantiated. The precursor system for (spoken) language evolution will be best understood when zooming out our theoretical and empirical lenses to include the vocal (and gestural) behavior of all great ape genera, including its neural and molecular substrates.…”