Ancient fingerprints and footprints maintain a visceral power to connect us — on a human level — to an individual from any time or place. Today, fingerprints from the ancient world survive as signs of humanity imprinted on the ceramics, waxen surfaces, or even cosmetic creams that survive from antiquity. But how did we come to view them as scientific signatures that could be used to identify criminals or lost children? What role does fingerprint analysis play in archaeology today? The science and pseudoscience surrounding the study of fingerprints has a long history.

The modern study of fingerprints in order to identify humans is called dactylography, a technical field which takes its name from the Greek word for finger, δάκτυλος. Hundreds of ancient prints have been transmitted via objects dating back to ancient Mesopotamia and beyond. For instance, a number of prints survive on tablets from Sumerian scribal schools called edubas, which trained scribes to write in cuneiform during the Old Babylonian period (ca. 2000–1600 BCE). In comments to Hyperallergic, Moudhy Al-Rashid, a post-doctoral researcher at the University of Oxford, remarked on the prevalence of such imprints on cuneiform tablets:

Clay tablet are not easy to shape or inscribe without smudging. In Nippur, a scribal school known as “House F” provides some archaeological information about the physical environment for education in Babylonia. Students made rough drafts. Particularly at the beginnings of their scribal careers, while first coming to grips with the medium of clau, they would have impressed as many fingerprints as wedges. Writing, after all, is a physical act.

As Dr. Al-Rashid notes, even seasoned scribes could have a slip of the hand and leave their own fingerprints on a document. Quickly written receipts or jotted exercises on clay tablets meant that the clay was often not as smoothed and polished as, say, a copy of the Epic of Gilgamesh for the Royal Library would be. Frustrated writers sometimes even bit into tablets. An Old Babylonian school text from Nippur has a cuneiform lexical text, but also has teeth marks from a young student, age 12 to 13. Al-Rashid notes the student may have bitten into the tablet in order to break it in half.

This Old Babylonian school text from Nippur not only preserves part of a cuneiform lexical text known today as “Proto-Ea”, but also bears the teeth marks of a student, aged 12 to 13, who may have bitten into the tablet to break it #Iraq pic.twitter.com/I7cBBHoLus — Dr. Moudhy Al-Rashid (@Moudhy) April 19, 2018

Far from simply transmitting echoes of the past, such markings are now being reexamined for what they can tell us about the individuals who left them. Scholars like forensic archaeologist Kimberlee S Moran, a professor at Rutgers University, have begun to point to the necessity for archaeologists and researchers of the past to identify and record fingerprints left on antiquities. In an article on ancient Mesopotamian clay sealings and tablets, Moran noted the import of digital archaeologists who are beginning to identify and keep records of the fingerprints they come across in databases. While the use of fingerprints as a human marker of identity is a relatively recent practice and science, modern fingerprint technology has been helpful to archaeologists.

By adapting the modern use of Automated Fingerprint Identification Systems (AFIS) for residual fingerprints left on antiquities, Moran believes we can better understand how people sealed documents in the ancient Near East. Such analysis may also help us to better understand conceptualizations of the individual within a community: “Both positive and negative results from this research will have ramifications for the current theories on the use of sealing, the extent of literacy, and the individual active in the community and society at large.”

As Moran and others have demonstrated, fingerprints are capable of revealing a great deal more about antiquity than we currently recognize, particularly in regard to gender. In an article focused on early ceramic production at Tell Leilan in Northeast Syria, Mesopotamian archaeologist Akiva Sanders looked at the gender roles evidenced from fingerprints left on pottery from 3400 to 1700 BCE. As Sanders notes:

Since 1999, several studies have confirmed a uniform difference between average male and female fingerprint ridge density in populations from around the world … ceramics of all types were formed and finished by both male and female potters. This result suggests that before the rise of urbanism and the state at Tell Leilan, pottery production was not a gendered task.

This means that archaeologists can begin to study the gender of potters at various periods by looking at the fingerprints they left in clay. Sanders’ study has also had a significant impact on the traditional idea that men were the primary producers of such pottery in antiquity by challenging these assumptions with scientific data.

The scientific analysis of gender as evidenced by fingerprints may yet tell us more about the male and female artisans in the Near East, but the methods may also help us to better understand the making of Greek and Roman pottery as well. Ceramics from the classical Mediterranean hold hundreds of subtle markings from the hands of potters. Last year, classicist Julie Hruby won a Mellon New Directions grant to apply modern forensics techniques in fingerprint analysis to antiquity in order to look at the gender of Minoan and later Greek ceramicists.

Other fingerprints left on objects from antiquity can simply tell us about the daily life of everyday people in the past. When a tin container was found during excavations in 2003 of a Roman temple within Tabard Square in London, archaeologists were amazed to see fingerprints surviving in what was surmised to be cosmetic cream, thousands of years later. Moreover, hundreds of rooftiles, pavements, and walls from the ancient world hold the fingerprints and footprints of both animals and humans — allowing us to better reconstruct the animals in an around urban and suburban areas in the ancient Mediterranean.

The allure of identifying artists through their fingerprints has not dissipated. As Hyperallergic recently reported, the left thumbprint of Leonardo da Vinci was found a few months ago on a medical drawing held within Britain’s Royal Collection, along with a smudged print from Da Vinci’s left index finger on the reverse of the drawing. The collection’s paper conservator, Alan Donnithorne, remarked that the Renaissance artist and inventor must have “picked up the sheet with inky fingers.” While the handwriting of the great inventor and artist was of interest, it was the uniquity of his fingerprint that captured popular interest.

The application of new forensic approaches to archaeological objects and manuscripts may hold great potential, but these methods are not without caveats. In order to understand the potential of historical fingerprint analysis, it is critical that we also be aware of its sordid and racist past — as well as current limitations. In the late 19th century, it was the Victorian polymath and notorious eugenicist Sir Francis Galton who systematized the science of fingerprints to identify individuals — an approach which would then be applied to identify criminals. As forensic anthropologist and bioarchaeologist Kristina Killgrove noted to me:

The basic ridge pattern of fingerprints was discovered in 1823, but popularized later in the 19th century by Francis Galton, Charles Darwin’s cousin, who was interested in heredity, race — and eugenics. He didn’t really think of fingerprints in a forensic context, though, and they weren’t used that way until the turn of the 20th century. In 1901, the New York City Civil Service Commission began requiring fingerprints for job applications. By the 1920s, fingerprints were a quick and easy way to identify people.

Killgrove remarked that the largest modern fingerprint database is AFIS—the automated fingerprint identification system which archaeologists have now been inspired to replicate for cross-comparing data from the ancient world. She also hastens to note that while AFIS can allow close cross comparison, it is the fingerprint analyst who makes the final determination. It is not as computationally easy as shows like Bones or NCIS can make it out to be.

The second cousin of Charles Darwin, Galton not only coined the term “eugenics” but was also a notorious racist who believed in the existence of higher and lower races, using his fingerprint research to hammer home ostensible differences in races. In an editorial to The Times, Galton once noted that “Chinamen” should be introduced into Africa in order to replace black men. And in his 1892 book Finger Prints, Galton explained his beliefs in differences between races expressed in their fingerprints:

The Jews have, however, a decidedly larger proportion of Whorled patterns than other races, and I should have been tempted to make an assertion about a peculiarity in the Negroes, had not one of their groups differed greatly from the rest. The task of examination has been laborious thus far, but it would be much more so to arrive with correctness at a second and closer approximation to the truth.

Forensic anthropologists are still trying to figure out whether ancestral (rather than racial) differences in fingerprints can be relied upon. A 2015 study did show slight differences between European-Americans and African-Americans within a small sample size. The evidence in these recent studies may point to ancestral heritage being coded in the ridges on our fingers in subtle ways, but this cannot and should not be used (as Galton did) to argue for the superiority of one population of people over another. Ann Ross, a professor of Anthropology at North Carolina State University who co-authored the 2015 study, remarked on the caveats of using fingerprints to study ethnic differences:

A lot of additional work needs to be done, but this holds promise for helping law enforcement … And it’s particularly important given that, in 2009, the National Academy of Sciences called for more scientific rigor in forensic science — singling out fingerprints in particular as an area that merited additional study.

As all of these studies show, advances in fingerprint analysis are leading archaeologists and historians in new and exciting directions, from using the technology on medieval fingerprints on left on wax seals to arguing for more female ceramicists in antiquity based on Mesopotamian pottery. However, it is important not to overstate what such data can tell us, or overstate the abilities of a computer to accurately assign gender, ancestry, or age. Trained artists, forensic archaeologists, and scientists still play a significant role in what we do with this new fingerprint technology and how we use the data to rewrite the annals of history to include more than just famous male artists who signed their works — and perhaps give a bit more credit to largely unknown artisans, scribes, and students.