I suggest that not only art but the entire switch to behavioral modernity came when those in any Stone Age society who lacked the genetic capacity to trance spontaneously were enabled to do so by the discovery and subsequent systematic exploitation of plant hallucinogens or one of the physical methods of trance induction. The hypothesis is that it was this “democratization” of altered states of consciousness, the possibility for the entire community to share in the life-changing visions and encounters that had previously been limited to a very few, that brought new, more open, more creative, more innovative, more flexible, more intuitive, and, frankly, more intelligent ways of thinking to a point of “critical mass” in society after society and ushered in the single most decisive shift ever to have occurred in human evolution. We need not be surprised that the archeological record shows this moment being reached at different times in different places, sometimes with intervals of thousands of years between the awakening of one group and another. If the trigger factor in every case was the discovery of reliable means to enter altered states of consciousness, and if this first discovery was often accidental, then we would not expect to find modern human behavior emerging everywhere all at once, but rather in stages and somewhat randomly—which is in fact what we see in the archeological record. Once the process had started, however, it could not be stopped, as people who did not know how to use altered states of consciousness would sooner or later have encountered people who did and would have learned from them.

From Graham Hancock’s Supernatural: Meetings with the Ancient Teachers of Mankind, London: Arrow Books, 2006 (first published in 2005), pp. 505-506.