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: (a) a reduction in reactive aggression, (b) the sophistication of language structure (with emerging grammars initially facilitating the transition from physical aggression to verbal aggression); and (c) the potentiation of pragmatic principles governing conversation, including, but not limited to, turn‐taking and inferential abilities. (...) 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 a specific form of communication governed by persuasive reciprocity—a trait of human conversation characterized by both competition and cooperation. In turn, both early crude forms of language, well suited for verbal aggression/insult, and later more sophisticated forms of language, well suited for persuasive reciprocity, significantly contributed to the resolution and reduction of (physical) aggression, thus having a return effect on the self‐domestication processes. 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 were engaged in a positive feedback loop with linguistic innovations, and where gene‐culture co‐evolution and cultural niche construction were the main driving forces. (shrink)

We propose that human self-domestication favored the emergence of a less aggressive phenotype in our species, more precisely phenotype prone to replace (reactive) physical aggression with verbal aggression. In turn, the (gradual) transition to verbal aggression and to more sophisticated forms of verbal behavior favored self-domestication, with the two processes engaged in a reinforcing feedback loop, considering that verbal behavior entails not only less violence and better survival, but also more opportunities to interact longer and socialize with more conspecifics, ultimately (...) enabling the emergence of more complex forms of language. Whereas in the case of self-domestication sexual selection has been proposed to work against physical aggression traits, in the case of verbal insult the selection has been proposed to work in favor of verbal aggression. The tension between these two seemingly opposing forces gets resolved/alleviated by a tendency to replace physical aggression with verbal aggression, and with verbal behavior more generally. This also helps solve the paradox of the Self Domestication Hypothesis regarding aggression, more precisely why aggression in humans has been reduced only when it comes to reactive aggression, but not when it comes to proactive aggression, the latter exhibiting an increase with the advent of modern language. We postulate that this feedback loop was particularly important during the time period before 50 kya, arguably between 200 kya and 50 kya, when humans were not fully modern, neither in terms of their skull/brain morphology and their behavior/culture, nor in terms of their self-domestication. The novelty of our approach lies (i) in giving an active role to early forms of language in interacting with self-domestication processes; (ii) in providing specific linguistic details and functions of this early stage of grammar (including insult and humor); (iii) in supplying neurobiological, ontogenetic, and clinical evidence of a link between (reactive) aggression and (reactive) verbal behavior; (iv) in identifying a variety of proxies of the earlier stages in evolution among cognitive disorders; and (v) in identifying specific points of contact and mutual reinforcement between these two processes (self-domestication and early language evolution), including reduction in physical aggression and stress/tension, as well as sexual selection. (shrink)

Language evolution resulted from changes in our biology, behavior, and culture. One source of these changes might be human self-domestication. Williams syndrome (WS) is a clinical condition with a clearly defined genetic basis and resulting in a distinctive behavioral and cognitive profile, including enhanced sociability. In this paper we show evidence that the WS phenotype can be satisfactorily construed as a hyper-domesticated human phenotype, plausibly resulting from the effect of the WS hemydeletion on selected candidates for domestication and neural crest (...) function. Specifically, we show that genes involved in animal domestication and neural crest development and function are significantly dysregulated in the blood of subjects with WS. We also discuss the consequences of this link between domestication and WS for our current understanding of language evolution. (shrink)