Jaynes's 1976 theory that human consciousness arose only ~3000 years ago — earlier humans had a 'bicameral mind' that heard one half of their brain as gods speaking to them.
From Wikipedia
Bicameralism is a type of legislature that is divided into two separate assemblies, chambers, or houses, known as a bicameral legislature. Bicameralism is distinguished from unicameralism, in which all members deliberate and vote as a single group. As of 2022, roughly 40% of the world's national legislatures are bicameral, while unicameralism represents 60% nationally and much more at the subnational level.