A comparison of cranial fluctuating asymmetry between the two sexes in a Joseon Dynasty population of Korea

Abstract

SUMMARY: Cranial fluctuating asymmetry (FA) has been used to examine developmental stress levels in various populations. In bioarchaeological studies, developmental stress can be an important factor for inferring standard of living in a population. However, the crania of a Joseon Dynasty population have only been studied in terms of its morphological characteristics. In this regard, the cranial FA of the two sexes from a Joseon Dynasty population of Korea were compared here for examining their aspects of living conditions in relation to developmental stress and socio-cultural factors. In this study, 77 individuals (39 males and 38 females) who belong to the 15th to the early-20th centuries from Seoul and Gyeonggi province in Korea were investigated. Nineteen three-dimensional landmarks on the vault and basicranium were collected using MicroScribe G2X. The coordinate data were aligned into a common coordinate plane by Procrustes least-squares superimposition. Procrustes ANOVA was adopted to evaluate FA at a population level. The FA of males and females were compared with t-test using SPSS 18. There was statistically insignificant difference in FA between the two sexes in the Joseon Dynasty population. The result was interpreted to reflect both relatively high developmental stress and sex-related discrimination in the population. It was postulated that relatively high developmental stress could increase difference in FA between the two sexes in the prenatal term compared to the postnatal term because sex-related discrimination cannot be practiced before birth and males have lower stress resistance than females. Then, the difference between the two sexes in the cranial FA could be decreased during postnatal development related to sex-related discrimination, resulting in insignificant FA difference of the two sexes in spite of high developmental stress of the Joseon Dynasty population. The results will be useful for comparing and reconstructing living conditions of ancient Korean populations.