Ritual, emotion, and sacred symbols : The evolution of religion as an adaptive complex

This paper considers religion in relation to four recurrent traits: belief systems incorporating supernatural agents and counterintuitive concepts, communal ritual, separation of the sacred and the profane, and adolescence as a preferred developmental period for religious transmission. These co-occurring traits are viewed as an adaptive complex that offers clues to the evolution of religion from its nonhuman ritual roots. We consider the critical element differentiating religious from non-human ritual to be the conditioned association of emotion and abstract symbols. We propose neurophysiological mechanisms underlying such associations and argue that the brain plasticity of human adolescence constitutes an "experience expectant" developmental period for ritual conditioning of sacred symbols. We suggest that such symbols evolved to solve an ecological problem by extending communication and coordination of social relations across time and space.

The material record and the antiquity of language

One view of language origins sees it as ancient and selection-driven; the other as recent and emergent. Such disagreement occurs because language is ephemeral, detectable only by indirect proxies. Because internalized language and symbolic thought are tightly linked, the best archaeological proxies for language are symbolic objects. Nothing indicates convincingly that any hominid behaved symbolically prior to Homo sapiens, which originated 200kyr ago but started behaving symbolically only 100kyr later. Most probably the necessary neural underpinnings arose exaptively in the extensive developmental reorganization that gave rise to anatomically distinctive Homo sapiens, and were recruited subsequently via a necessarily behavioral stimulus. This was most plausibly the spontaneous invention of externalized language, in an isolate of Homo sapiens in Africa, that initiated a feedback process between externalized structured language and internalized language/organized thought. These subsequently spread in tandem throughout a species already biologically predisposed for them. Despite its qualitatively remarkable result, this exaptive process would have been perfectly routine and unremarkable in terms of evolutionary mechanism.