AN EXPANSIVE collection of skulls from defeated enemies symbolized power in many early societies. The Jivaro tribe in the Amazon would remove skulls and shrink soft tissue to make “shrunken heads.”
The Munduruchu of Brazil decapitated fallen enemies and elaborately prepared the heads for display.
But the skulls collected 2,000 to 1,500 years ago by the Nasca civilization on the coast of Peru may have served a different purpose; scientists believe that figuring out that purpose could be important to understanding how civilization progressed in South America.
Originally discovered by the late Alfred Louis Kroeber—an American anthropologist from the University of California at Berkeley—the heads were collected from the Nazca Valley on the arid coast of southern Peru during expeditions in 1925 and 1926.
The heads were well preserved due to the area’s dry climate—they even retained traces of soft-tissue and hair. For the past 80 years the heads have been stored at the Field Museum in Chicago.
Scientists call the heads “trophy heads” because the heads have a hole in the front of them so that they can be hung from cords. Although portrayals of trophy heads were common in pre-Colombian ceramics, textiles and sculpture, the actual heads are hard to come by. Excavations in Peru have yielded only 150 of these heads so far.
Due to the lack of physical evidence, researchers look to pottery for clues as to the purpose of these heads. “Illustrations on some pots depict warriors and trophy heads,” says Patrick Ryan Williams, Associate Curator of Archaeological Science at the Field Museum in Chicago. “But there are also scenes that link trophy heads to agricultural fertility. Mythical creatures depicted on some pots carry trophy heads as well.”
A 2001 study led by Professor Sloan R. Williams of the University of Illinois at Chicago showed that most of the 18 trophy heads housed at the Field Museum came from males between the ages of 18-25. Although that demographic suggests that the heads belonged to warriors, there were heads from women and children as well.
“As of 2001 we thought they were warriors,” says Ryan Williams. “That’s why this [recent] analysis we undertook was so critical to address this question: were these heads warriors?”
Researchers theorized that if the heads were trophies from war, they would have come from people who lived outside of Nasca territory.
In the 2008 study, led by Professor Kelly J. Knudson from Arizona State University, researchers compared samples of tooth enamel from 16 heads with the skeletons of 13 mummified bodies from the Nazca area.
By comparing the signatures of different forms of strontium, oxygen and carbon, the researchers could determine whether the two groups lived in and ate the same food produced in the same area.
“You are what you eat,” said Williams, “and the elements you consume become a part of your bones’ chemical signature.”
Because the comparison showed that the trophy heads came from the same population as the people who collected the heads, researchers believe that the heads did not come from expansionary warfare and were collected for some other purpose.
“For the Nasca, these heads could have a very different meaning. We need to keep in mind that heads turned into trophies may represent violence but, they may represent something else,” Williams says. “They me be a way to honor someone.”
Williams believes that understanding the Nasca culture is especially important because they were the predecessor to the Wari—one of the area’s most influential societies in South America who predated the Inca by 4 centuries.
“This small scale agrarian society was succeeded by an empire with regional authority,” Williams said. “For the first time people were governed by others who lived hundreds of miles distant. Understanding how this came about may help us better understand how these forms of government first emerged.”
Published in Americas magazine by Chris Hardman