Incognito: The Secret Lives of the Brain

by David Eagleman

In 1976, the American psychologist Julian Jaynes proposed that until late in the second millennium B.C.E., humans had no introspective consciousness, and that instead their minds were essentially divided into two, with their left hemispheres following the commands from their right hemispheres.29 These commands, in the form of auditory hallucinations, were interpreted as voices from the gods. About three thousand years ago, Jaynes suggests, this division of labor between the left and right hemispheres began to break down. As the hemispheres began to communicate more smoothly, cognitive processes such as introspection were able to develop. The origin of consciousness, he argues, resulted from the ability of the two hemispheres to sit down at the table together and work out their differences. No one yet knows whether Jaynes’s theory has legs, but the proposal is too interesting to ignore.