A different kind of data storage
In the arid Supe Valley of Peru, about 184 kilometers north of Lima, the Norte Chico civilization built the oldest known city in the Americas. This society, also known as the Caral-Supe, flourished between 3000 BCE and 1800 BCE, contemporary with the pyramid-builders of Egypt. At their largest urban center, Caral, archaeologists found remnants of a complex data-recording system that predates writing in the Americas: the quipu.
A quipu (meaning "knot" in the Quechua language) is a device made from strings of cotton or camelid fibers. Information is encoded by the type of knot, its position on the string, the color of the string, and even the direction of the ply. The oldest quipu found at Caral pushes back the known use of this technology by thousands of years. The society at Caral was complex, with monumental architecture, including six large pyramidal structures and sunken circular plazas, suggesting a government that needed a method for record-keeping.
Knots, numbers, and administration
The Norte Chico quipu was likely a tool for administration. While later Inca quipus are known to have used a decimal system to record numbers, the full details of the older Caral system are still being investigated. Researchers believe these knotted strings were used as ledgers to track census data, tax obligations, and the inventory of storehouses. The economy of Norte Chico depended on agriculture—growing cotton, beans, and squash—and maritime resources like anchovies, all of which would require careful tracking.
The development of the quipu happened in a society with other unusual characteristics. The Norte Chico people constructed their cities without making pottery, a technology common to most other ancient civilizations. They also show little evidence of warfare. Their focus was on agriculture, trade, and communal civic projects. The quipu is a solution for managing a complex society without a character-based writing system.