A new study of ancient fingerprints preserved on China’s Terracotta Army suggests that women and juveniles participated alongside adult men in the production of the famous ceramic figures.
Researchers analysed 79 well-preserved fingerprints found on 36 terracotta soldiers from Unit T23 in Pit 1 of the mausoleum of Qin Shi Huang, the first emperor of a unified China.
Using a Bayesian statistical model, the researchers estimated that the fingerprint assemblage comprises approximately 45% adult males, 32.7% adult females and 22.3% juveniles under the age of 15.
The findings provide new evidence concerning the people involved in one of the largest manufacturing projects undertaken during the Qin Dynasty.
Fingerprints left by ancient craftspeople
The Terracotta Army consists of thousands of life-sized ceramic soldiers, horses and other figures buried as part of the vast funerary complex constructed for Qin Shi Huang during the 3rd century BC.
Previous research has investigated how the figures were manufactured and how production may have been divided between different workshops.
Inscriptions have identified craftspeople associated with imperial and local production, while studies of clay composition and manufacturing techniques have provided evidence for the organisation of workshops supplying the mausoleum.
However, determining the age and sex composition of the people physically manufacturing the figures has remained considerably more difficult.
Fingerprints accidentally impressed into clay before firing provide one potential source of biological evidence.
For the new study, researchers examined 79 clear fingerprints preserved across 36 figures. Individual soldiers contained between one and five suitable prints.
The analysis focused on mean ridge breadth – the average distance between fingerprint ridges – which can provide population-level information relating to age and sex.
Women and juveniles may have participated in production
Rather than using conventional linear regression methods, the researchers applied a Bayesian mixture model designed to account for uncertainty and overlap between different demographic groups.
The resulting model attributed approximately 45% of the fingerprint assemblage to adult males and 32.7% to adult females, while a further 22.3% was attributed to juveniles.
For the purposes of the study, the researchers defined juveniles as individuals below the age of 15, based on evidence concerning age-related legal responsibility in surviving Qin Dynasty texts.
The results challenge the assumption that the manufacture of the Terracotta Army was undertaken exclusively by adult men.
There is also documentary evidence for women and younger people participating in other forms of state-supervised craft production during the Qin period.
Inscriptions found on Qin lacquerware, for example, contain terms referring to adult women, young girls and young boys involved in production.
The fingerprint evidence raises the possibility that a similarly diverse labour force participated in manufacturing objects for Qin Shi Huang’s mausoleum.
Results do not represent an exact workforce census
The researchers caution that the percentages produced by the model should not be interpreted as the exact demographic composition of the Terracotta Army workforce.
The figures describe the frequency of fingerprints within the analysed assemblage rather than the number of individual craftspeople who produced them.
One worker could have left multiple fingerprints, while others may have left no identifiable impressions.
The study also acknowledges potential biases resulting from human behaviour, differences between ancient and modern populations, and changes to ceramic dimensions during firing.
Another important limitation is that the model relies on a modern European reference dataset. Differences in fingerprint ridge dimensions between populations could therefore result in an overestimation of the proportion of females and juveniles.
Despite these limitations, the results indicate that the fingerprint assemblage cannot readily be explained by a workforce consisting exclusively of adult males.
Investigating the makers behind the warriors
The production of the Terracotta Army required the manufacture of thousands of large ceramic figures as part of the wider mausoleum complex of Qin Shi Huang.
Previous studies have proposed different models for how this enormous manufacturing programme was organised.
Some researchers have suggested that individual body components were mass-produced before assembly, while spatial studies and makers’ marks have indicated that multiple workshops may instead have been responsible for producing complete figures.
The new fingerprint study approaches the question from a different direction by examining traces inadvertently left by the craftspeople themselves.
According to the researchers, applying Bayesian population-level analysis to ancient fingerprints could provide a new method for investigating the organisation of craft labour at archaeological sites where suitable impressions survive.
The study, “Who produced Emperor Qin Shihuang’s Terracotta Army, China? A Bayesian mixture model approach to fingerprint age and sex determination”, has been published in the Journal of Cultural Heritage.
Sources : Science Direct