Full Idea
Around the time of the rise of the first great civilizations, the main gods changed sex, as the Great Goddess, or a raft of smaller goddesses, were demoted and male gods took their place.
Gist of Idea
During the rise of civilizations, the main gods changed from female to male
Source
Peter Watson (Ideas [2005], Ch.05)
Book Reference
Watson,Peter: 'Ideas: from fire to Freud' [Phoenix 2006], p.143
A Reaction
Why? War, perhaps?