Permanent economic inequality is unknown among mobile hunter-gatherers, but hereditary class distinctions between elites and commoners exist in some sedentary foraging societies. With the spread of agriculture, such stratification tends to become more pronounced. We develop a model to explain...

Until about 13,000 years ago all humans obtained their food through hunting and gathering, but thereafter people in some parts of the world began a transition to agriculture. Recent data strongly implicate climate change as the driving force behind the transition in southwest Asia. We propose a...