To coordinate larger-scale works and get labor done for the common good, central leadership evolved. This generated social hierarchies that could enforce, in a top-down way, the labor efforts that to workers did not seem to satisfy their immediate needs.
Central leadership also arose in order to store and distribute harvests for an entire year and keep a minimum of grains as seeds in the next season. Men, with their physical superiority, were the ones using chances to rise in the hierarchy. Women were easier to subjugate and force to work for the common good.
In due course, social hierarchies solidified and started to derail into unnecessary violent discipline. From there, forced labor and slavery were introduced.
With low seasons giving time to specialize in crafts and arts, and storage of harvests getting larger, it became attractive to assault neighboring villages and loot their cereals, along with products of crafts and art.
It made humans learn the taste of blood. Before, conflicts between neighboring groups usually boiled down to limited skirmishes for territory. But now that there was free time in the low seasons and popular food seemingly easily accessible, people’s genes proved able to make us murderously greedy.
This new type of inter-community thrive further contributed to inequality between the sexes as male warrior bands, after having killed the inimical men, raped the women and brought them home for slave work.
Something else influenced neighbor conflicts. The emerging type of warfare also grew in scale. Permanent farming allowed for large populations and in the low season men could be recruited in huge numbers for the armies. Moreover, because of population growth, the survival of communities got less in danger with losses of many lives in warfare. Armies of 50,000 to 100,000 soldiers were seen marching against enemies near and far in West Asia.
Yet another force reshaped patterns of conflict between neighbors. It had to do with men having grown used to top-down enforced labor discipline in the organization of farm work. This familiarity facilitated the organization of large armies in similar ways. It made many a soldier more afraid of the commander than of the enemy and fight nearly mechanically. Once a field battle was won, the lid of discipline was taken off and all hell broke loose for the surviving male and female enemies.
The Assyrians, in the valley down from the Zagros Mountains were farming started, got especially known for their highly skilled warfare. And once they had conquered another community, they used extreme cruelty to destroy the enemy’s sense of identity and any hope of rebellion. Their ferocity went so far as to skin prisoners alive, cut off body parts, including tongues, and displayed collections of human skulls.
And so, Fertile Crescent humanity set of for a future of oppression, exploitation, limitless cruelty, wild greediness and mass murder, all beyond what a community needs for survival.