The distance between us and the Stone Age shaman is not genetic but cultural. The primal shaman's practices can take him or her to the highest levels of human development, maturity, integration and enlightenment. In Buddhist teachings all beings have Buddha nature, even the grass under our feet. To believe our culture is at a critical juncture that makes it possible for us to reach the highest state of consciousness is fine, but to say that earlier nature oriented cultures are barred from this possibility is a mistake. DiZerega says that Wilber makes such a mistake.
Cultures can facilitate or impede such processes of transformation.
For centuries in the West, e.g., religious persecution made cultivation of human consciousness extremely difficult and even highly dangerous. In New Age literature there are books on the transformation of consciousness and the multiorgasmic nature of human sexuality. The Tantric and Taoist practice of cultivating sexual energy to balance masculine and feminine energies yields higher and higher levels of integration up to complete unity of awareness. This is described in great detail in Taoist alchemical texts in use for centuries. There is a series of stages and centers of energy described in the old texts.