A cultural change occurred roughly 40,000 years ago. For the first time, there was evidence of belief in unseen agents and an afterlife. Before this time, humans did not show widespread evidence of being able to think about objects, persons, and other agents that they had not been in close contact with. I argue that one can explain this transition by appealing to a population increase resulting in greater exoteric (inter-group) communication. The increase in exoteric communication triggered the actualization of a dormant potential for greater syntactic computational power; specifically it triggered syntactic movement. Syntactic movement, in turn, made possible variable binding, which crucially figures into cognition by description, a naturalistic analogue of Russell's knowledge by description. Cognition by description made possible the ability to conceive of things one had never experienced, such as mythological beings, places only visited by the dead, and so forth. The Amazonian Pirah (a) over tilde provide some corroboration for this hypothesis, since they exhibit the combination of traits here attributed to Middle Paleolithic individuals, namely exclusively esoteric (intra-group) communication, evident lack of syntactic movement, and a limitation to knowledge (cognition) by acquaintance.