The Agricultural Revolution was a worldwide phenomenon. During this time humans learned how to collect more food per unit area, and there was a subsequent population explosion. Despite this abundance, the quality of human life did not improve. As the population grew quickly during the first few thousand years of the Agricultural Revolution, there was more work and less time for relaxation.

Harari uses the example of wheat to trace the effects of the Agricultural Revolution on the human condition. Wheat was a demanding crop, requiring humans to clear fields, remove weeds in the hot sun, watch for pests, build fences, keep watch, and transport water to the fields. Humans bodies suffered, and people were forced to live near their fields, transforming their way of life. Wheat, Harari argues, domesticated us and not the other way around.

Humans at the time didn't see how their lives were losing quality in the face of the increasing abundance of food. The luxuries of safety and lack of hunger became necessities as people began to take them for granted, then to rely on them, until they couldn’t live otherwise. As people settled into communities instead of moving frequently to forage, diets became less varied and nutritious, and crowded villages facilitated the spread of disease.