At some point in the development of the human race, as it went from simpler to more complex societies during the agricultural revolution, humanity also went from basically non-warring, collaborative and gender egalitarian (great oversimplification) to hierarchical, competitive, and warring.

Growing complexity gave the first push, but what were the social mechanisms that enabled the changes: their had to follow a change in the way people thought, a change so vast that it shaped the last 10,000 years. there will be no peace until the thinking is uncovered and the valuye system dismantled (or should I say re-manteled).