The Health Impacts of Increasing Social Inequality in Late Prehistoric Northeast Thailand

Evidence for increasing social inequality and a concurrent health deterioration has been observed in Iron Age (420BCE-500CE) northeast Thailand. Inequality is commonly considered to be represented by variations in quantities of grave goods allocated to individuals, although the relationship between grave goods and status has not been tested. Whether deteriorating health relates to this purported inequality or other biocultural processes is also not fully understood, and further investigation of this issue has been limited by the poor preservation of Iron Age skeletal remains. The late Iron Age site of Non Ban Jak (300-800CE) provides diverse grave goods assemblages alongside well-preserved human remains, allowing investigation of the relationship between quantities of grave goods, which may reflect social inequality, and health. Non Ban Jak is also significant for the presence of two conjoined mounds within the site boundaries that have different material culture suggestive of different social affiliations, and for the presence of house burials at the site. This thesis presents an investigation of stress and social inequality at Non Ban Jak and has two primary aims: 1) to determine whether grave goods distributions and spatial segregation, which may be representative of social inequality, relate to non-specific stress levels at late Iron Age Non Ban Jak; and 2) to situate the findings from Non Ban Jak in a regional context of social change and health deterioration. To investigate levels of non-specific stress during childhood at the site, age at death profiles, long bone lengths and linear enamel hypoplasia (LEH) were investigated in an assemblage of 196 individuals, comprising 71 adults and 125 subadults. The possibility of social inequality was explored through a quantitative grave goods analysis and an investigation of spatial segregation of different age and sex groups, individuals from different mortuary phases, and of differing stature or LEH presence. Although diachronic changes in the frequencies of non-specific stress indicators suggested that stress reduced over time at Non Ban Jak, the variation in stress between the different age and sex groups and between the mounds suggested that experiences of stress varied by social identity. Analyses of grave good quantities and spatial segregation demonstrated that these varied between different age, sex and mound groups and may be suggestive of inequality. Furthermore, differences in grave goods quantities suggest the presence of two social classes, represented by the ‘poorer’ east and ‘richer’ west mound, while variation in grave goods quantities among burial clusters identified in the west mound suggested that rankings within these classes were flexible. Age-based variation in grave goods does not appear to be related to health, although sex-based variation in both grave goods and non-specific stress indicators suggests that females occupied a lower status position in the community. Smaller quantities of grave goods in the eastern mound corresponded to higher levels of stress. Variation in grave goods quantities among different social groups at Non Ban Jak is suggestive of a hierarchical community structure, although more detailed mortuary analyses are required to confirm this hypothesis. Fluctuations in grave good quantities among burial groups further suggests that this society was transitioning between unstable and stable forms of hierarchy. Land ownership and house burial may have been used to signal wealth and transmit it through family lines, creating and perpetuating inequality between corporate groups represented by burial clusters and between the mounds. Within a regional context, Non Ban Jak appears to show deteriorating health consistent with proposed models of health change, while evidence of transition and inequality at the site supports the model of social change. However, this thesis demonstrates that experiences of stress were not uniform among Iron Age communities and that health is difficult to generalise at a regional level. Despite ongoing stress, the people of Non Ban Jak appear to be an innovative community, adapting social customs and new ideas to their use in a dynamic period of social change in Southeast Asia