August 11, 2005
Peru’s ancient “khipu” strings were ledgers -study
By Maggie Fox, Health and Science Correspondent
WASHINGTON (Reuters) - The Incas' curious knotted strings
called khipu were probably used by bosses and accountants to
keep track of taxes and tributes and carried both words and
numerical information, two experts said on Thursday.
The dyed bunches of string, also spelled quipu by some
scholars, have confused outsiders since Spanish conquerors
first described them 500 years ago. Most experts agree they are
ledgers of a sort but no one has been able to decipher them.
"The Spaniards were bewildered by them," said Gary Urton of
Harvard University in Massachusetts, who worked on the study.
"Four hundred years later, we aren't much better off."
Theories abound -- that they are a kind of binary code,
that they are simply dull collections of numbers, or that they
are one of the earliest forms of human writing.
Urton and Carrie Brezine turned to computers for help.
"We recently undertook a computer analysis of 21 khipu from
the Inca administrative center of Puruchuco, on the central
coast of Peru," they wrote in their report, published in the
"Results indicate that this khipu archive exemplifies the
way in which census and tribute data were synthesized,
manipulated, and transferred between different accounting
levels in the Inca administrative system."
And they found what appears to be a word -- the name of a
"We hypothesize that the arrangement of three figure-eight
knots at the start of these khipu represented the place
identifier, or toponym, Puruchuco. We suggest that any khipu
moving within the state administrative system bearing an
initial arrangement of three figure-eight knots would have been
immediately recognizable to Inca administrators as an account
pertaining to the palace of Puruchuco."
FOUND IN FIVE COUNTRIES
Just last month archeologists said they found a khipu on
the site of the oldest city in the Americas, called Caral. They
said their find supported the idea that the knotted bunches of
string were complex written works that were in use for 4,500
Now Urton and Brezine say their findings fit in with what
is known about the Inca's hierarchical society and widespread
empire across what are now Peru, Ecuador, Chile and parts of
Argentina and Bolivia.
"This work gives us some sense of how this complex
information was compiled, manipulated, shared and archived in
the Inca hierarchy," Urton said in a statement. "Instructions
of higher-level officials for lower-level ones would have
moved, via khipu, from the top of the hierarchy down."
"In the reverse direction, local accountants would forward
information on accomplished tasks upward through the
hierarchy," he said.
Urton has previously argued that khipu may also have been
used as calendars. Some khipu have been found in burial sites
that have 730 strings grouped in 24 sets -- equivalent to the
number of days and months in two years.