The vast Inca Empire was the largest in the Americas until 1533 C.E., when the Spanish conquered its capital, Cusco, in what is today Peru. Besides pillaging, the conquistadors also chronicled Incan customs. One shocking ritual was capacocha, in which children were killed or abandoned on frigid peaks. Now, a chemical analysis of four Incan mummies finds that children were fattened before being sacrificed to the weather god, Illapa, and other deities.
In recent years, archaeologists searching the Andes have found shrines containing the frozen, mummified bodies of children adorned with necklaces, headdresses, and bracelets. In some cases, the children were killed with blows. Others appear to have been left to die in the cold. In 1996, for example, excavations in Peru uncovered a 15-year-old girl, whom the archaeologists named Sarita. Three years later, researchers found more sacrificed children on top of Argentina's Llullaillaco volcano: a 15-year-old girl, a 7-year-old boy, and a 6-year-old dubbed Lightning Girl because her corpse had been struck by lightning.
A team led by bioarchaeologist Andrew Wilson of the University of Bradford, U.K., has now analyzed the isotopic composition of the four children's hair to trace the last months of their lives. The ratio of carbon isotopes, for example, is affected by what kind of plants made up their diets, whereas the ratio of nitrogen isotopes depends on how much meat they consumed.
The team found that most of the children began eating more elite food as their deaths approached. The older girl, for example, shifted from a diet probably largely based on potatoes to one suddenly rich in animal protein and maize about a year before she died; the two other Llullaillaco children showed similar although less pronounced patterns. Sarita's diet, on the other hand, did not fit this pattern, showing a decrease in maize consumption as she approached her death. The findings are reported online this week in the Proceedings of the National Academy of Sciences.
Wilson and his co-workers conclude that the nutritious diets were part of the preparations for capacocha, which included elevating children from lower classes to a special status worthy of the Inca deities. The ritual included a long, strenuous journey to the mountaintops. The authors also suggest that the sacrifices had the Machiavellian purpose of inspiring fear and awe in the rest of the Inca.
Kelly Knudson, a bioarchaeologist at Arizona State University in Tempe, says hair analysis could be useful where bodies are well preserved, such as in the Andes. But Tamara Bray, an archaeologist at Wayne State University in Detroit, Michigan, says that the results in the study are not clear-cut. For example, the 15-year-old appears to have been the best fed of the four children, but Lightning Girl actually seemed to have higher status based on the value of the artifacts found with her body. Bray also questions just how much fear and awe the high-elevation sacrifices would have inspired: "Few citizens of the Inca Empire would have actually been witness to such sacrificial events."