Answer by Balaji Viswanathan:
- Childbirth: A childbirth takes the prime strength out of a woman for a minimum of 15 months (9 months of pregnancy + 6 months of recovery/nursing kid). Multiply that by 5-6 childbirths and that is close to 10 years of prime life. Until the 20th century medical marvels, life expectancy was pretty low and mother mortality pretty high. Most women thus never had the spare time and strength to dominate the society.
- Physical strength: Men have more brute strength than women. In ancient societies, physical strength mattered a lot. Almost all civilizations built armies to survive the raiding armies. This gave the warriors (most often men) a preeminent role and strong warriors got to decide a lot in the society
- Farming: Until the arrival of agriculture, men and women had almost equal roles in a hunter-gatherer society. The invention of agriculture gave men a lot of advantage by controlling food production (requires one to manage heavy beasts in farm and heavy things like ploughs). Women were also now required to bear even more children as agriculture demanded bigger families.
- Men focused on the intangibles: To play the traditional stereotypes, Women are usually more grounded due to their strong interaction with family and people immediately around them. Men travel a lot for warring and also often had a lot of spare time to think. Thus, men thought of "higher" level things – nationalities, religion, morality and made sure they codified power into things that were advantageous to them. Almost all major religions were founded by men and all major wars were started by men, for instance.
- Network effects: Power is partly based on network effects. Men were strongly networked when it comes to power (or slit each others throats). Even when a strong woman took up the power as Queen, it was hard for her to sustainably bring other women into her ring as most other suffered from the physical handicap. Thus, power reverts back to men after the end of a successful queen.
- Self-fulfilling prophesies: As men consolidated the power since the start of the civilization, self-fulfilling prophesies about how women are incapable of ruling, emerged. These kept more women out of dreaming about power.