Why are some cultures collectivist and others individualist? The answer might literally be rice. The Rice Hypothesis: wet rice farming required coordinated irrigation and synchronized planting—your neighbor's failure meant your failure. Wheat farming depended on rainfall, allowing household independence. Thomas Talhelm tested this within China. Same country, different crops, measurable cultural differences—even among urban populations who never farmed. Culture isn't mysterious. It's structural.

1. Introduction