A new study suggests that the cultivation of easily taxable cereal grains like wheat and barley was key to the emergence of the first large human societies around 5000 years ago. Researchers analyzed language evolution and anthropological data to show how states formed protection rackets around grain production. This shift also led to writing for tax records and a decline in population health.
The origins of the first states have long puzzled scholars, with agriculture often cited as a driver of civilization. However, a study published in Nature Human Behaviour argues that not all farming was equal: cereal grains such as wheat, barley, rice, and maize provided the surplus needed for taxation, enabling state formation.
Agriculture first appeared around 9000 years ago, invented independently at least 11 times across four continents. Yet large-scale societies only emerged about 4000 years later, starting in Mesopotamia, followed by Egypt, China, and Mesoamerica. Kit Opie at the University of Bristol, UK, and Quentin Atkinson at the University of Auckland, New Zealand, investigated this gap using phylogenetic methods on language family trees, which map cultural relationships, combined with data from hundreds of pre-industrial societies.
Their analysis revealed that states were unlikely to form without widespread cereal production but highly probable when grains were the main crop. Intensive agriculture correlated with states, but the direction was reversed: "It looked more likely that it was the states causing the intensification, rather than the intensification causing the states," Opie said. Once established, states could invest in irrigation and fertilization to boost output, creating taxable surpluses.
Grains proved ideal for taxation due to their fixed fields, visible growth, predictable harvests, and long storage life. "Root crops like cassava or potatoes were hopeless for taxation," Opie noted. States acted as "protection rackets," defending fields in exchange for taxes. Writing emerged to record these levies, with adoption far more likely in taxing societies.
States also phased out non-grain crops like roots and fruits to maximize taxable land, a move linked to Neolithic population growth but also poorer health, shorter stature, and dental issues. Critics like Laura Dietrich at the Austrian Archaeological Institute caution that the approach may oversimplify regional differences, such as why intensified agriculture led to states in southwest Asia but not Europe. David Wengrow at University College London emphasizes there was no single trigger for state emergence worldwide, pointing to ritual organization in ancient Egypt over mere taxation.