Social diversity and the origins of complex society at Ban Non Wat, Thailand

The rise of state societies is one of the major transitions in human prehistory. In mainland Southeast Asia, the origins of state society share similarities with many of the classic states studied worldwide: a background of simpler, loosely-integrated agrarian communities, some of which may have herded livestock or even still hunted and gathered. As people grew in number, specialised in their occupations, and agglomerated over many generations, state societies arose among these locally dense, interdependent populations.

Early states were often hierarchical, but they were also heterogeneous, often cosmopolitan, and composed of specialised socioeconomic groups that both competed and interacted in ways that manifested the state itself. People may have differentiated themselves across multiple dimensions: social spheres, occupations, residential neighbourhoods, and common family links. Among these, it is crucial to understand the role of kinship, which may have been the earliest organising principle of complex societies. As both population size and the scale of social differences grew, differences may have depended less and less on kinship ties, or, alternatively, come to be inherited along kinship lines. In the archaeology of early states, however, such phenomena have been very difficult to study because artefacts and other material remains are indirect evidence with respect to the migrations and differences of people.

What is needed is direct evidence, from the prehistoric individuals themselves. Within the wider collaborative archaeological project on the origins of Angkor, I seek to measure isotopes in archaeological skeletons from the site of Ban Non Wat, in the Mun Valley of northeast Thailand. Here, the rise of social complexity may have occurred in a context that was often matrilineal (female-centred), which is unusual among pre-state societies. Ban Non Wat features the largest site-sample of human remains yet discovered in prehistoric Southeast Asia. With over six hundred excavated skeletons, ranging from the Neolithic to the Bronze Age to the Iron Age, the sample provides an unprecedented chance to investigate changes in kinship and social differentiation from simple agrarian origins to a complex, hierarchical and specialised society, becoming part of the Angkor civilization.

In samples of tooth enamel, my Ph.D. students and I will measure isotopes (chemical elements with different atomic masses) from hundreds of human skeletons from Ban Non Wat. Strontium isotopes, which differ from place to place, indicate the geographic area from which each person obtained his/her diet during childhood (when the enamel was forming). Carbon and nitrogen isotopes, which we will measure in both bone collagen and tooth enamel, inform about diet. Using radiocarbon dating to refine the chrononology, we will investigate how immigration patterns and diet changed through time, how these changes may have differed among women and men, and how they related to burial positions and artefacts. Such patterns serve as clues to the specialization and/or group affiliation of each individual.

By first identifying locals versus non-locals, we will identify basic aspects of kinship, particularly the immigration of women (patrilocality) versus men (matrilocality) into Ban Non Wat. In addition, by collaborating with colleagues from University of Otago, we will identify correlations through time between the geographic origins of individuals (isotopes), genetic relatedness (skeletal and dental traits), social distinctions (burial treatments, artefacts) and quality of life (skeletal biology) of individuals and groups. In this unique part of the prehistoric world, these multiple lines of evidence will provide an entirely new perspective on crucial social aspects of early state origin, including changes in social differentiation, migration, and kinship through time.