A selective sweep occurs when a new, beneficial gene mutation appears and quickly sweeps across a population, erasing the genetic diversity that existed prior to the sweep. Similarly, languages have “swept” across continents as the cultures they belonged to gained unbeatable advantages (often agricultural or military), resulting in losses of language diversity from earliest human history to the present day. Today, half the population of the world speaks one of only thirteen languages.
These are not controversial claims. More controversial is the idea that human prehistory (and even history) hosted a wide variety of human consciousness, not just language, and that these disparate kinds of subjective consciousness were destroyed upon contact with new forms of consciousness. Most dramatically, Julian Jaynes famously argued (in The Origin of Consciousness in the Breakdown of the Bicameral Mind) that human consciousness changed drastically in the past few thousand years, from an archaic bicameral form in which one side of the brain shouted orders and the other obeyed, to a modern, introspective form. My claim is not so extreme: I simply argue that there are and have been many forms of human consciousness, varying in particular ways, that we retain the “hardware” capability for many forms of consciousness, and that humans are constrained into particular mental states by their cultures, especially through group ritual (or lack thereof). In order to explore this claim, it is helpful to think about our own form of consciousness in detail – a form of consciousness that is novel, contagious, and perhaps detrimental to human flourishing compared with more evolutionarily tested forms of consciousness running on the same hardware.