Drilling Away the Spirits : A Worldwide Study of Trepanation

Abstract

Trepanation is a worldwide phenomenon that is most often studied on a case-by-case basis, with few comparisons cross-culturally or through time and with no agreement as to why it was practiced. Earlier theories have suggested ritualistic and magico-therapeutic purposes and have proposed a higher frequency of trepanations in adult males as a result of injuries sustained in warfare and gender-specific ritual practices. A compilation of case reports and information on trepanation is, therefore, vital for a bioarchaeological study of the procedure. This research catalogues and describes 297 incidences of trepanation in the extant literature in order to present a worldwide comparison of the practice and ascertain reasons for its performance. This thesis collects and reviews all of the cases of trepanation reported in the English-language scholarly literature to look for overall patterns that might lend credence to one explanation or another and to examine temporal and geographic variation. This study is of potential significance because it establishes a baseline review of all cases that others can use to draw conclusions about the reasons for this fascinating practice worldwide or in specific localities. Four questions are answered in the Discussion section. Are more men than women trepanned because men are more likely to be involved in warfare as the literature suggests? Yes, in fact more than twice the number of males than females were trepanned. Is there any evidence to support cultural explanations or is this a residual category used for when skeletal remains show no evidence of pathology? It is difficult to determine if a procedure was done for cultural reasons, especially when there are no written records. Additionally, lack of skeletal pathology is linked to the osteological paradox, the fact that individuals who are the sickest die before manifesting any skeletal evidence. A third question is whether or not there is any evidence to support the theory of diffusion, which states that trepanation originated in one or two centers and then diffused to other areas. This is also difficult to prove, although there are two centers that have evidence of trepanation from the Mesolithic: Eastern and Western Europe. And lastly, is there any cultural evidence to support subadult trepanation or only biological evidence? Most of the trepanned juvenile population showed biological factors that would necessitate trepanation, except for one case. Out of the total observed sample, sex was mentioned in 215 out of all 293 cases. Out of these 215 individuals 52.9% (155) were male, 20.45% (60) were female, and 26.62% (78) individuals' sex was indeterminate. Only 209 out of the total 293 individuals' age-at-death were reported. The majority of the sample of both sexes was under 30 years of age. These data sources revealed that slightly more adult males were trepanned than females and children. The few trepanned children showed evidence of developmental disorders such as scurvy and hydrocephaly, but this may not necessarily have been the reason for trepanation. Since the trepanned males did not always display possible related pathologies, it is highly likely that they were trepanned for both biological and ritualistic reasons.