INTERPLAY BETWEEN LANGUAGE, NAVIGATION AND KIN SELECTION

It has been suggested that human language emerged as either a new, critical faculty to handle recursion, which linked two other existing systems in the brain, or as an exaptation of an existing mechanism, which had been used for a different purpose to that point. Of these two theories, the latter appears more parsimonious, but, somewhat surprisingly, has attracted less attention among researchers in the field. Navigation is a prime candidate for a task that may benefit from being able to handle recursion, and we give an account of the possible transition from navigation to language. In the described context, it appears plausible that the transition adding the crucial component of human language was promoted by kin selection. We show that once language is present among its speakers, it reinforces the mechanisms of kin selection, boosting such behaviour that benefit one's kin, and any such behaviour in turn boosts the use of language. The article also describes a mechanism through which language is used in lieu of kin markers to promote altruistic behaviour between potentially large communities of unrelated individuals.