Pre-industrial societies share a set of economic characteristics that is remarkably consistent across nearly 10,000 years of human history. The advent of agriculture enabled complex societies to form, but necessitated collective organization for defense first from existing nomadic cultures that might raid fixed settlements and then from other complex societies that may have developed capacity to expand militarily. These pre-industrial societies were consistently hierarchical; the bottom 80% of the population were peasant farmers, above them would be some various groups of craftsmen, traders, and soldiers, and at the top sat some type of authoritarian ruler. The hierarchical organization succeeded in offering protection and stability, while maintaining low living standards for the peasants and glacial rates of technological change. What technological progress did occur led to population growth, which gradually diminished any initial improvements in average income. This Malthusian trap persisted up until the industrial revolution; the result was that nearly all technological change over 10,000 years of human history contributed to population growth in classically conservative hierarchies with little change to the lives of average people.