Human self-domestication and the evolution of pragmatics

As proposed for the emergence of modern languages, we argue that modern uses of languages (pragmatics) also evolved gradually in our species under the effects of human self-domestication, with three key aspects involved in a complex feedback loop: (i) a reduction in reactive aggression, (ii) the sophistication of language structure (with emerging grammars initially facilitating the transition from physical aggression to verbal aggression); and (iii) the potentiation of pragmatic principles governing conversation, including, but not limited to, turn-taking and conversational implicature. Our core hypothesis is that the reduction in reactive aggression, one of the key factors in self-domestication processes, enabled us to fully exploit our cognitive and interactional potential as applied to linguistic exchanges, and ultimately, to evolve sophisticated turn-taking, as well as complex inferential abilities, both of which seem to require fine-tuned coordination and cooperation. Supporting evidence for our proposal, as well as grounds for further testing, comes mainly from the consideration of cognitive disorders, which typically simultaneously present abnormal features of self-domestication, including aggressive behavior, and problems with pragmatics and social functioning. While various approaches to language evolution typically reduce it to a single factor, our approach considers language evolution as a multifactorial process, with each player acting upon the other, engaging in an intense mutually reinforcing feedback loop. Moreover, we see language evolution as a gradual process, continuous with the pre-linguistic cognitive abilities, which we also see as engaged in a positive feedback loop with linguistic innovations, with gene-culture co-evolution and cultural niche construction as the main driving forces.