As far as our narrative of the rise of social differentiation goes, archaeologists posit that the earliest pre-agricultural communities were for the most part egalitarian. With the rise of agriculture comes the increase in social differentiation. However, how and when this occurred is not well understood. In order to determine status differentiation there has been a strong reliance on mortuary evidence. Differences in status are reflected in the variation in grave goods, with more exotic and rare goods signaling a higher status. A new study by Bentley et al. (2012) goes beyond mortuary data and uses strontium isotopes in addition to mortuary evidence in order to determine the earliest case of documented status differentiation.
The spread of farming, which correlates with the rise of status differentiation, spread over five centuries in the across European plains. This is represented by the Linearbandkeramik (LBK) Neolithic cultural assemblage which dates from 5500 BCE to 5000 BCE. The interpretation of increasing social differentiation among the LBK communities is based on architecture, grave good assemblages, and the circulation of exotic goods like Spondylus shells. However, Bentley et al. (2012) note that these models range from interpretations of the early farmers as egalitarian to highly stratified, often using evidence from single sites or case studies. Since status is correlated with reproductive advantages, looking at gene flow by modeling sex based mobility differences could be a crucial piece of evidence towards better understanding this period. They propose that by assessing diet, health and place of origin from human remains, they will be able to create interpretations about dispersion and differentiation.
The primary piece of evidence is derived from strontium isotope analysis. As I discussed in an earlier post, strontium is the new hot archaeology trend. Strontium is found in rocks, water and soils, which is then conveyed into the food chain, and ingested by humans where it is substituted in the bone for calcium. The 87Sr/86Sr ratio in human tooth enamel can be used as a “geographic signature from childhood”. This means that by analyzing the teeth of an individual we can determine where they were when their teeth were mineralizing.
This study consists of more than 550 samples from eastern France to northern Hungary where 87Sr/86Sr ratios could be obtained from tooth enamel of over 300 individuals. These remains come from a a diverse range of LBK cemeteries, including the earliest LBK cemetery of Vedrovice, Czech Republic (5400–5250 BCE), Aiterhofen, Germnay (5300–5000 BCE), Schwetzingen, Germany (5100–5000 BCE), Nitra, Slovakia (5100–5000 BCE), Kleinhadersdorf, Austria (5300–4900 BCE), Ensisheim, France (5200–5000 BCE), and Souffelweyersheim, France (5200–5000 BCE). In addition to this, they collected information about the strontium ratios of the geological regions. However, because of the problems associated with collecting this information (such as biopurification and the biasing effects of agriculture) they rely on looking at the averages of strontium among human groups rather than comparing with geology. “By measuring, in units of SD [standard deviation], the distance of each individual’s Sr isotope ratio from the site mean, we can then pool all seven sites together to examine patterns of variance among individuals across all of the sampled LBK sites”.
In addition to this, they compare strontium ratios in males with the presence or absence of ground stone adzes in their burial assemblage. Bentley et al (2012) argue that this artifact is labor intensive and distinctive of the LBK, making it a potential status symbol. They also examine differences in variation of strontium between males and females to determine whether one is moving more than the other, which can indicate matrilineal or patrilineal communities. The goal of the study is to determine whether there are correlations between strontium isotope ratios, the presence of ground stone adzes and sex.
They found that there was a significantly larger range and wider variation among female strontium isotopes ratios than males. This means that females are more likely than males to have originated from a different region than the one they were buried in. They also found that males who were buried with ground stone adzes had less variability in strontium ratios than males without adzes. They interpret this as meaning that males with these potentially high status goods had specific ties to land which meant they were moving less. This could also mean that land was being passed down through families, therefore causing the family members to stay in the area. They conclude that this has implications for the model of Neolithic expansion and change. Male inheritance of land means that males stay where they are whereas females marry and move elsewhere. “Because patrilocality, intergenerational wealth transfer, and agriculture tend to correlate in small-scale societies, a simple explanation is that unequal and inherited land access developed in time among the early farmers in Central Europe”.
The use of strontium in this manner is quite original, and combining it with mortuary evidence creates a compelling argument. Studies like this are important because they show the utility of multiple lines of evidence. However, I think the argument does require some expansion and a greater discussion of the broader archaeological context. Given that the report is only 5 pages, it is likely we will hear more about this project in the future and hopefully expansion will be forthcoming.
Bentley, R., Bickle, P., Fibiger, L., Nowell, G., Dale, C., Hedges, R., Hamilton, J., Wahl, J., Francken, M., Grupe, G., Lenneis, E., Teschler-Nicola, M., Arbogast, R., Hofmann, D., & Whittle, A. (2012). Community differentiation and kinship among Europe’s first farmers Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1113710109