Multidisciplinary analyses and ancient DNA reveal social inequality and mobility in the Central Plains during the Eastern Zhou period in China

Abstract

The Eastern Zhou period (771–221 BC), characterized by social stratification, was marked by important inequality. Here the authors analyse 32 skeletons from Songzhuang Cemetery in Henan Province using sex-specific peptides, ancient DNA and isotopes to explore multidimensional inequality in sexes, diet and mobility. DNA and proteomic analyses show that young women were marginalized as sacrificial victims (22 out of 26 human sacrifices were female). Carbon and nitrogen isotopic analyses suggest dietary differences by social class, with the nobility consuming more high-protein and millet-based diets than sacrificial companions, who themselves show intra-group dietary variation (d13Cbone,nobles = -8.6‰; d13Cbone,human sacrifice group one = -10.9‰; d13Cbone,human sacrifice group two = -14.1‰; d15Nbone,nobles = 11.6‰; d15Nbone,human sacrifice group one = 8.5‰; d15Nbone,human sacrifice group two = 7.7‰). Enamel and dentin isotope data indicate that these dietary inequalities were established from childhood (d13Cenamel,nobles = -1.5‰; d13Cenamel,human sacrifice group one = -3.8‰; d13Cenamel,human sacrifice group two = -6.9‰). Strontium and oxygen isotope evidence shows that a high proportion of the nobles were non-local migrants. Genetic analysis reveals a genealogy linking four noblewomen to a sacrificial victim, highlighting the importance of kinship and marital alliances in maintaining social status. Despite class rigidity, dental isotope sequences in M18 reveal that two individuals experienced childhood dietary shifts, indicating rare class mobility.