The Emergence of Modern Languages: Has Human Self-Domestication Optimized Language Transmission?

The Emergence of Modern Languages: Has Human Self-Domestication Optimized Language Transmission? Antonio Benítez-Burraco and Vera Kempe. Front. Psychol., April 17 2018. https://doi.org/10.3389/fpsyg.2018.00551

Introduction

Our uniquely human ability to learn and use languages (aka language-readiness) has been hypothesized to result from species-specific changes in brain development and wiring that habilitated a new neural workspace supporting cross-modular thinking, among other abilities (Boeckx and Benítez-Burraco, 2014; see Arbib, 2012, 2017 for a similar view). Strikingly, behavioral modernity did not emerge on a par with cognitive modernity. On the contrary, it is only well after our split from Neanderthals and Denisovans that modern behavior becomes evident around the world (see Mellars et al., 2007; but also Hoffmann et al., 2018; for tentative evidence of behavioral modernity in Neanderthals). This emergence of modern behavior has been linked to the rise of modern languages, i.e., exhibiting features such as elaborate syntax including extensive use of recursion. The potential of these languages to convey sophisticated meanings and know-how in ways that allows sharing of knowledge with others is assumed to have arisen in a reciprocal relationship with complex cultural practices (Sinha, 2015a,b; Tattersall, 2017). Thus, even if not its main trigger, complex language is at the very least a by-product and facilitator of modern behavior.

Because the human brain and human cognition have remained substantially unmodified since our origins, behavioral modernity and modern languages are assumed to be the product of cultural evolution via niche construction (Sinha, 2009, 2015b; Fogarty and Creanza, 2017). This may include feedback effects of culture on our cognitive architecture in the form of the creation of “cognitive gadgets” (Clarke and Heyes, 2017) through small modifications in learning and data-acquisition mechanisms like attentional focus or memory resources (Lotem et al., 2017), but without involving significant neuro-anatomical changes (Figure 1). However, this explanation may be insufficient: Recent research suggests that aspects of the human distinctive globular skull and brain might have evolved gradually within our species in response to accompanying genetic changes, reaching present-day human variation between about 100 and 35 thousand years ago (kya), in parallel with the emergence of behavioral modernity (Neubauer et al., 2018). Thus, it may not be entirely appropriate to equate neuro-anatomical modernity with cognitive modernity; instead, the language-ready brain can be conceived of as a brain with the potential for cognitive modernity. Here we argue that these neuro-anatomical and concomitant behavioral changes are largely manifestations of human self-domestication, which constitutes a possible pathway toward cognitive modernity and sophisticated linguistic abilities. We focus specifically on parenting and teaching behaviors as foundations of cultural transmission processes that may have facilitated the exploitation of our cognitive potential and, ultimately, the emergence of modern languages.