Language evolution in a context of increased socialization: the self-domestication approach

Because language does not fossilize, and because scripts only appeared very recently, the sort of languages spoken in Prehistory has been mostly a speculative issue. In this chapter, we rely on the human self-domestication hypothesis (i.e. the claim that our species experienced an evolutionary process similar to domesticated animals, that was triggered by, and resulted in, increased prosocial behaviour) for clarifying this unsolved question. We will argue that this trend towards increased socialization would have favoured selected behavioural changes, but perhaps cognitive and physical changes too, that enabled the sophistication of languages through a cultural mechanism. This would have ultimately resulted in the emergence of the two types of languages found in present-day human societies: esoteric and exoteric, which are optimized, respectively, for communicating with close people, or for interacting with strangers within complex societies.