Skeletal remains are an important source of evidence for learning about warfare and interpersonal violence in past populations. A new study done by Andrushko and Torres (2011) in the American Journal of Physical Anthropology assesses the prevalence of warfare in Incan populations over three time periods based on the trauma suffered by human remains. Andrushko and Torres argue that the majority of current information on warfare and the rise of the Incan during the 15th and 16th centuries comes from Spanish chronicles and first hand accounts from the diaries of foreigner missionaries, conquistadors or explorers. In these documents, Incan supremacy over other South American cultures is attributed to warfare. However, it is unknown to what extent this accounts are true, or are embellishments of a historical past. The emphasis on war may have been placed into accounts in order to justify the Spanish conquest. In order to determine the validity of these sources and clarify history, Andrushko and Torres propose to use analysis of warfare related trauma in skeletal remains as a source of independent evidence.
Andrushko and Torres analyzed the remains of 454 adult skeletons from 11 sites in the Cuzco region of Peru, dating from 600-1532 CE. They focus on cranial trauma as determining the presence of warfare, and compare it against the historic accounts of weapons used by the Incans. The sites are lumped into three time periods in order to compare the rise of the Incans and the presence of warfare. The first period is the Middle Horizon, dating 600 to 1000 CE, which serves as the baseline for warfare prior to the rise of the Inca. The sample includes four sites and 36 individuals. The second period is the Late Intermediate Period, dating 1000-1400 CE, and representing the era of the rise and expansion of the Inca. This includes five sites and 199 individuals. The final period is the Inca Imperial Period, dating from 1400 to 1532 CE, representing the era of Inca control. This includes 9 sites with 219 individuals. By comparing the presence of warfare related cranial trauma in each of these periods they argue that they can determine whether war was the means by which the Inca gained power.
They found that during the Middle Horizon 8.3% of individuals had cranial trauma, in the Late Intermediate 23.6% had cranial trauma, and in the Inca Imperial 22.8% had cranial trauma. The archaeologists then divided the trauma into major and minor, with major being depression or trauma over 5cm indicative of warfare rather than accident. For major trauma, only one individual from the Middle Horizon had clear warfare related trauma, only 2.5% of individuals from the Late Intermediate had warfare related trauma, and 7.8% had this trauma in the Inca Imperial. Based on the assumption of major trauma equating warfare, it would appear that war wasn’t common until after the rise of the Inca.
Andrushko and Torres (2011: 370) conclude that “The ultimate implication of the present study is that Inca imperialism in the Cuzco region may have been less warfare dependent than some Spanish chronicles imply. Rather, Inca expansion was likely successful because it incorporated a range of strategies using militaristic, economic, political and ideological means”. While the authors admit that this estimate is conservative by only looking at cranial trauma and major injuries as evidence of warfare, they argue that these are the only clear indicators.
There are a number of very interesting pieces in this article, but I want to point out one benefit of this study and one downfall. First, the authors are using skeletal analysis as an independent line of evidence in which to test the conclusions of historical accounts. One of the problems in the past of doing archaeology where texts were available was that archaeologists took the text as truth and placed the archaeological evidence within the textual framework. Now, we recognize the bias of text, and use the archaeological record as a way to test the validity of the text and challenge prior constructed histories. The problem I see with this type of analysis is that there is such a narrow skeletal focus. While I usually argue for the use of the whole mortuary site and not just the remains, in this case it would have been beneficial to at least hear about the trauma of the complete body. By limiting it to cranial trauma the estimate for warfare related trauma is probably too conservative to draw any clear conclusions. Hopefully in the future, the archaeologists will address the whole suite of trauma on the skeletons.
Andrushko VA, & Torres EC (2011). Skeletal evidence for Inca warfare from the Cuzco region of Peru. American journal of physical anthropology, 146 (3), 361-72 PMID: 21959843