Shedding light on the treatment of individuals with disabilities in the late Middle Ages

FacebookXLinkedInWeChatBlueskyMessageWhatsAppEmail

 

image: 

The femoral fracture in grave 2399 with the tibia repositioned to show the 45-degrees angulation.

view more 

Credit: Photo: Nelly Hercberg, Cultural Museum in Lund.

The skeleton of a man with a severe dislocated fracture of the knee, found in a cemetery in Lund, southern Sweden, is helping to unravel the complexities of social attitudes towards individuals with disabilities in the late medieval period. The research combines traditional osteological methods and 3D modelling - a cutting-edge technique for viewing and studying traumatic injury and related skeletal changes - with contextual information from historical texts and digitized excavation records to build a more nuanced understanding of disability and care in the past.

The study, conducted by Blair Nolan of Lund University, Sweden and colleagues, and published in De Gruyter Brill’s Open Archaeology, is the first to apply this approach to medieval remains in the Nordic region.

The skeleton, referred to as individual 2399, belonged to a man of about 30 years of age who lived in the late Middle Ages (1300–1536 CE). At some point in his twenties, his left femur (thigh bone) was badly broken at the knee joint, leaving him unable to walk unaided until his death. The injury could have been caused by a kick from a horse or a heavy object falling on the knee, such as stone while working on a building. For the remainder of his life, he required a mobility aid to get around, such as crutches or a leg stand.

Contextual analysis of his skeleton revealed that the man received considerable short- and long-term care. Following his injury, he was likely given forms of pain relief available at the time, such as ointments made of lavender oil, opium and alcohol, and would have required help to clean and dress the wound. He also required regular treatment for inflammation of the bone marrow - osteomyelitis - which probably included opening the wound to drain the pus.

When the researchers analyzed historical records to deduce the social impacts of individual 2399’s disability, they uncovered a very complex picture.

Religious views of physical disability at the time were complicated: it could be considered both a punishment from God and a divine test requiring penance. Nevertheless, the Church promoted and took part in collecting and distributing alms for the disabled, and monasteries were the main providers of institutionalized medical care.

Other cultural attitudes can be deduced from the legal codes of the time. For example, penal punishments could include removal of body parts such as hands, feet, eyes, nose or ears, leading to an association of disability with criminality in some cases. Also, the severity of a disability was defined not just by how much the individual was impaired but also by its visibility. An injury that could be concealed by hair or clothing was considered less severe.

Despite these negative cultural views of disability, individual 2399’s social status was still high enough to afford him both long-term medical care and a prominent burial place in the cemetery. Individuals of higher socioeconomic status, such as members of the burgher class, strove to be buried as close to the church as possible, and individual 2399 was buried on top of the foundation stones at the base of a church tower. Thus, his higher social status may have outweighed the fact that he had a disability.

Nolan said: “Deducing social norms regarding physical impairment and disability from religious and legal texts is difficult because it presents an idealized perspective. We can enrich our understanding of disability and identity through detailed osteological and archaeological analysis.”

The paper can be found here: https://doi.org/10.1515/opar-2025-0043 

Large study traces prehistoric human expansion into South America, where genomic studies have been lacking

A large-scale genomic study of over 1,500 individuals from 139 underrepresented Indigenous groups across northern Eurasia and the Americas sheds new light on the ancient migrations that shaped the genetic landscape of North and South America. The results reveal distinct ancestry patterns and early diversification of Indigenous South American populations. The late Pleistocene saw the migration of humans from North Asia into North and South America beginning by at least 23,000 years ago, according to archaeological evidence. This expansion was rapid – genetic evidence suggests northern and southern Native American groups began diverging between 17,500 and 14,600 years ago, with human presence in southernmost South America confirmed by 14,500 years ago. However, many questions remain about this expansion and its impact on the genetic architecture of human populations across the continents, especially in South America, where high-resolution genomic studies are still lacking.

 

To address this knowledge gap, Elena Gusareva and colleagues developed a comprehensive, high-resolution genomic dataset comprising over 1,500 individuals from 139 ethnic groups – many previously unstudied. This dataset, containing more than 50 million high-quality genetic variants, was analyzed alongside ancient and modern DNA from Native American populations. This helped the authors investigate deep patterns of population history, migration, and adaptation. Gusareva et al. found that Siberian populations trace their ancestry to six ancient lineages, with West Siberian heritage broadly shared across the region. A notable population decline around 10,000 years ago may have been driven by climate change and the loss of megafauna. Moreover, genetic and archaeological evidence suggests that Native Americans diverged from North Eurasians between 26,800 and 19,300 years ago, with west Beringian groups like the Inuit, Koryaks, and Luoravetlans being their closest living relatives. In South America, four distinct Indigenous lineages – Amazonians, Andeans, Chaco Amerindians, and Patagonians – rapidly emerged from a common Mesoamerican origin between 13,900 and 10,000 years ago. The four lineages largely reflect distinct geographical and environmental regions, such as the Andes Mountains, the arid lowlands of the Dry Chaco, the humid tropical rainforests of the Amazon Basin, and the frigid polar climate of Patagonia. According to the authors, rapid geographic isolation of these groups likely reduced genetic diversity, particularly in immune-related HLA genes, which may influence susceptibility to infectious diseases.

Asians made humanity’s longest prehistoric migration and shaped the genetic landscape in the Americas

An international genomics study led by scientists from Nanyang Technological University, Singapore (NTU Singapore) at the Singapore Centre for Environmental Life Sciences Engineering (SCELSE) and Asian School of the Environment (ASE) has shown that early Asians made humanity’s longest prehistoric migration.

These prehistoric humans, roaming the earth over a hundred thousand years ago, would have traversed more than 20,000 kilometres on foot from North Asia to the southernmost tip of South America.

This journey would have taken multiple generations of humans, taking thousands of years. In the past, land masses were also different, with ice bridging certain portions that made the route possible.

Supported by the GenomeAsia100K consortium [1], the study was published this week in Science, which analyses DNA sequence data from 1,537 individuals representing 139 diverse ethnic groups.

The study involved 48 authors from 22 institutions across Asia, Europe and the Americas.

The researchers traced an ancient migratory journey that began in Africa, proceeded through North Asia and ended at Tierra del Fuego in modern-day Argentina, which is considered the final boundary of human migration on Earth.

By comparing patterns of shared ancestry and genetic variations that accumulate over time, the team was able to trace how groups split, moved, and adapted to new environments.

These patterns allowed the team to reconstruct ancient migration routes and estimate when different populations diverged.

The reconstructed routes gave a detailed picture of how early humans reached the far edge of the Americas, and the findings suggested that this pioneering group overcame extreme environmental challenges to complete their journey across millennia.

A key insight was that these early migrants arrived at the northwestern tip of South America, where modern-day Panama meets Colombia, approximately 14,000 years ago.

From this critical point of entry, the population diverged into four major groups: one remained in the Amazon basin, while the others moved eastward to the Dry Chaco region and southward to Patagonia’s ice fields, navigating the valleys of the Andes Mountains, the highest mountain range outside of Asia.

By analysing the genetic profiles of indigenous populations in Eurasia and South America, researchers from the GenomeAsia100K project have, for the first time, mapped the unexpectedly large genetic diversity of Asia.

Understanding migration and genetic resilience

The study also sheds light on the evolutionary consequences of such a vast migration.

Associate Professor Kim Hie Lim from NTU’s Asian School of the Environment, the study’s corresponding author, explained that the arduous journey over thousands of years had reduced the genetic diversity of the migrant population.

“Those migrants carried only a subset of the gene pool in their ancestral populations through their long journey. Thus, the reduced genetic diversity also caused a reduced diversity in immune-related genes, which can limit a population’s flexibility to fight various infectious diseases,” explained Assoc Prof Kim, a Principal Investigator at SCELSE and Vice-Director of GenomeAsia100K.

“This could explain why some Indigenous communities were more susceptible to illnesses or diseases introduced by later immigrants, such as European colonists.  Understanding how past dynamics have shaped the genetic structure of today’s current population can yield deeper insights into human genetic resilience.”

SCELSE Senior Research Fellow Dr Elena Gusareva, the study’s first author, said that these early groups settled into new ecological niches, and over hundreds of generations, their bodies and lifestyles evolved in response to the unique challenges of each region.

“Our findings highlight the extraordinary adaptability of early, diverse indigenous groups who successfully settled in vastly different environments. Using high-resolution whole-genome sequencing technology at SCELSE, we can now uncover the deep history of human migration and the genetic footprints left behind by the early settlers.”      

Importance of Asian representation in genetic studies

NTU Professor Stephan Schuster, the study’s senior author of the paper and the Scientific Director of the GenomeAsia100K consortium, said: “Our study shows that a greater diversity of human genomes is found in Asian populations, not European ones, as has long been assumed due to sampling bias in large-scale genome sequencing projects.”

“This reshapes our understanding of historical population movements and lays a stronger foundation for future research into human evolution. Our new insights underscore the importance of increasing the representation of Asian populations in genetic studies, especially as genomics plays a critical role in personalised medicine, public health, and the understanding of human evolution,” added Prof Schuster, who is the President’s Chair in Genomics at NTU’s School of Biological Sciences, and the Deputy Centre Director at SCELSE.

By tracing the impact of migration and isolation on genetic characteristics, the study offers insights into how different populations respond to diseases and how their immune systems have evolved.

The findings also help scientists better understand the genetic makeup of Native American populations and help policymakers to better protect and conserve native communities.

It also demonstrates how advanced genomic tools and global collaboration can deepen humanity’s understanding of human evolution and inform future medical and scientific breakthroughs.

###

---

[1] GenomeAsia100K is a non-profit consortium focused on sequencing and analysing 100,000 Asian genomes to drive population-specific medical advancements and precision medicine. See website for more information.

---

Journal

Science

DOI

10.1126/science.adk5081 

New evidence of how ancient human relatives in South Africa used their hands

FacebookXLinkedInWeChatBlueskyMessageWhatsAppEmail

 

image: 

The fossil hands of Australopithecus sediba (around two million years old) and Homo naledi (around 250,000 years old) show that these South African hominins may have had different levels of dexterity, as well as different climbing abilities.

view more 

Credit: © Tracy Kivell

To the point

• Different hand use: Two ancient human relatives, Australopithecus sediba and Homo naledi, had different finger bone morphologies that indicate they used different types of hand grips, both when using tools and when climbing
• Internal structure of the finger bones: A. sediba had a mix of ape-like and human-like features, while H. naledi had a unique pattern of bone thickness, suggesting different loading patterns and possible grip types.
• Human Evolution: Ancient human relatives adapted to their environments in diverse ways, balancing tool use, food processing, and locomotion, challenging the traditional view of a single, linear transition from upright walking to advanced tool use.

Scientists have found new evidence for how our fossil human relatives in South Africa may have used their hands. Research led by Samar Syeda, postdoctoral researcher at the American Museum of Natural History, together with scientists at the Max Planck Institute for Evolutionary Anthropology, the University of the Witwatersrand, University of Kent, Duke University and the National Geographic Society, investigated variation in finger bone morphology to determine that South African hominins not only may have had different levels of dexterity, but also different climbing abilities.

This new research focuses on two, almost complete fossil hand skeletons found in South Africa.  One is the hand of Australopithecus sediba, first discovered in 2010 at the site of Malapa and dated to approximately two million years old.  The other hand skeleton is from the more recent, but perhaps more enigmatic, Homo naledi, first found in 2015 deep within the Rising Star Cave system and dated to around 250,000 years ago. 

Neither hominin has yet been found in direct association with stone tools, but several aspects of their hand and wrist morphology suggest that they had a degree of hand dexterity much more similar to that of humans than to living chimpanzees or gorillas. “Since stone tools are found in South Africa by at least 2.2 million years ago (and in East Africa by as early as 3.3 million years ago), and many primates are all excellent stone tool users, it is not surprising that A. sediba and H. naledi would be dexterous tool users as well. However, how exactly they used tools and if they manipulated their tools in similar ways is unclear,” says senior author, Tracy Kivell.

Moreover, both A. sediba and H. naledi are also found with many other bones of their skeleton that preserve ape-like features, particularly bones of their upper limbs, that would be advantageous for climbing. If these features reflect actual climbing in these individuals or are simply evolutionary hold-overs from an ancestor that climbed, is a longstanding debate in palaeoanthropology.

Fossil hands reveal ancient human behavior

To help address these questions, Syeda and her colleagues investigated variation in the internal structure—the cortical bone—of the fingers in A. sediba and H. naledi. Bone is a living tissue that can adapt its structure in response to how we use and load our skeleton during life, getting thicker where loads are higher and thinner where loads are lower. Therefore, variation in the internal cortical thickness can provide new insights in how these two hominin fossils may have actually used their hands during their lifetimes.

“We found that A. sediba and H. naledi show different functional signals in the cortical bone structure of their fingers,” says Samar Syeda, lead author of the study.  In A. sediba, the distribution of the cortical bone within the proximal and intermediate phalanges of most of its fingers is like that of apes. However, bones of its thumb and pinky finger are more like those of humans. Syeda concludes that “these two digits are more likely to reflect potential signals of manipulation because they are less often used or experience less load during climbing or suspensory locomotion. When we combine these results with the remarkably long, human-like thumb of A. sediba, it suggests that A. sediba used its hand for both tool use and other dexterous behaviours, as well as climbing.”

Homo naledi's hands show unique grip pattern

H. naledi, in contrast, is unusual in showing a human-like signal in its proximal phalanges (the bones that articulate with the palm) but an ape-like signal in its intermediate phalanges (the bones within the middle of the fingers). “This distinct pattern was unexpected and indicates that H. naledi likely used and loaded different regions of its fingers in different ways,” says Syeda. This kind of loading pattern is typical of only certain grip types used today, like crimp grips, used often by rock climbers, where the surface is grasped primarily by just the tips of the fingers. H. naledi also has unusually highly curved finger bones, particularly for a hominin that lived at the same time as the earliest members of our species, Homo sapiens, which is another indication that it used its hands for locomotion.

While more research is needed to further test if H. naledi may have used crimp-like grips or climbed rocks, it is clear that throughout human evolution there were different ways of combining enhanced dexterity for tool use and food processing with the continued need to use the hands to climb, be it trees or rocks, within the South African palaeolandscape. “This work offers yet more evidence that human evolution is not a single, linear transition from upright walking to increasingly better tool use, but is rather characterized by different ‘experiments’ that balanced the need to both manipulate and to move within these past environments,” says Kivell.

---

Journal

Science Advances

DOI

10.1126/sciadv.adt1201 

World-famous Schöningen spears are 100,000 years younger than previously claimed, new research suggests

Scientists have analysed amino acids locked in snail shells to establish a new age for the world’s oldest complete wooden hunting weapons

Peer-Reviewed Publication

University of York

FacebookXLinkedInWeChatBlueskyMessageWhatsAppEmail

 

image: 

The Schöningen spears as presented at the exhibition of the “Paläon” Research Museum in Schöningen, Germany.

view more 

Credit: Photo: MINKUSIMAGES. With kind permission of the copyright holder: Niedersächsisches Landesamt für Denkmalpflege (NLD)

The study used recent advances in a dating method known as “amino acid geochronology” – a technique refined by a research group led by Professor Kirsty Penkman at the University of York.

By analysing amino acids locked within snail shells buried within the sediment that preserved the spears, the research team was able, for the first time, to directly date material from the exact layer of earth in which the spears were found.

At the time of the discovery of the first spears in the mid-1990s, they were thought to be around 400,000 years-old, but that estimate was later revised to approximately 300,000 years. However, these age estimates were based on analysis of the underlying sediment layers.

The researchers, whose findings are published in the journal Science Advances, emphasise that this younger age estimate does not diminish the importance of the Schöningen discoveries. Instead, they say it further highlights the site's importance as a marker in the study of human evolution.

Co-author of the paper, Professor Kirsty Penkman, from the Department of Chemistry at the University of York, said: “This new dating evidence places the remarkable Schöningen spears within the Middle Palaeolithic period, the time of the Neanderthals.”

First author Dr. Jarod Hutson of the Leibniz Zentrum für Archäologie (LEIZA) in Mainz, Germany,  said “The Schöningen spears are so significant because, unlike older sites, they offer compelling evidence of sophisticated hunting strategies which would have required better cognitive abilities and the development of more complex communication, planning and social structures. The updated timeline for Schöningen now aligns it with a growing number of sites which together indicate a significant leap in early human hunting capabilities during this period.”

The site at Schöningen, Lower Saxony, was located at a lakeside where rapid sedimentation caused the exceptional preservation of organic materials, including the impressive arsenal of hunting weapons and other wooden implements, along with the butchered remains of hunted prey, which primarily consisted of horses.

Previous archaeological investigations analysing these horse remains, notably by the MONREPOS Archaeological Research Centre and Museum for Human Behavioural Evolution near Neuwied, a LEIZA department closely linked to the Johannes Gutenberg University in Mainz, have revealed evidence of seasonal hunting of small groups of horses along the shores of the ancient lake, with over 50 individual animals documented.

These findings point towards well-organised hunting parties, where individuals undertook coordinated and specific roles to ensure successful kills of larger and more challenging prey. The redating of the Schöningen site implies a notable increase in the level and complexity of human cooperation by approximately 200,000 years ago.

Amino acid geochronology - the biochemical approach central to the redating of the site - takes advantage of the fact that amino acids, the building blocks of protein, come in two forms: left-handed and right-handed versions of the same molecule.

When a creature is alive, its proteins are made only of the "left-handed" version. But after it dies, some of these slowly change into the "right-handed" version. By measuring how much of each version is left in certain fossils, scientists can work out how long ago that creature lived. The researchers looked at the tiny "trapdoors" (called opercula) of small freshwater snails called Bithynia. These little doors are made of a mineral that traps the amino acids inside for millions of years, like a perfect time capsule. The scientists took samples of these snail trapdoors from the same layer of earth where the famous spears were found.

They compared the amounts of the two types of amino acids in the opercula from Schöningen with those from other opercula found across northern Europe. Another  research team in Madrid carried out further tests on horse teeth and tiny organisms called ostracods also found in the same sediment layer, and the results backed up the idea that the Schöningen site is younger than previously thought.

Co-author of the study, Ellie Nelson, a PhD student in the Department of Chemistry at the University of York added: “Groundbreaking refinements in amino acid geochronology are allowing us to date Palaeolithic archaeological sites with greater accuracy than ever before, reshaping our understanding of this pivotal era in human history. This innovative method allows us to measure time signals trapped within the crystals of fossilised shell and tooth enamel in any part of the world across a range of archaeological sites. The enhanced accuracy holds immense potential for unlocking the long-held secrets of the Palaeolithic.”

Revised age for Schöningen hunting spears indicates intensification of Neanderthal cooperative behavior around 200,000 years ago is published in the journal Science Advances. 

The study was carried out by researchers from the University of York (UK), Leibniz Zentrum für Archäologie (Germany), National Museum of Natural History (Washington D.C), Lower Saxony Institute for Historical Coastal Research (Germany), University of Bremen (Germany), Johannes Gutenberg University Mainz (Germany), Museum of Prehistory and Archaeology of Cantabria (Spain), Universidad Politécnica de Madrid (Spain), Lund University (Sweden), Max Planck Institute for Evolutionary Anthropology (Germany), University of the Basque Country (Spain) and Complutense University of Madrid (Spain). The amino acid dating at York was thanks to funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 865222 - EQuaTe).  

Study reveals vast Aztec trade networks behind ancient obsidian artifacts

New archaeological research by Tulane University and the Proyecto Templo Mayor in Mexico reveals how obsidian – a volcanic glass used for tools and ceremonial objects and one of the most important raw materials in pre-Columbian times – moved across ancient Mesoamerica and shaped life in its capital, Tenochtitlan. The study sheds new light on the economic networks, rituals and political influence of the Mexica (Aztec) Empire.  

Published this week in Proceedings of the National Academy of Sciences, the study analyzed 788 obsidian artifacts excavated from the Templo Mayor of Tenochtitlan, the main temple and core of the Mexica Empire located in what is now Mexico City. The research represents the largest compositional study of obsidian ever conducted at the site.

Archaeologists found that while the Mexica primarily used green obsidian from the Sierra de Pachuca source, they also acquired obsidian from at least seven other locations, including regions beyond their political borders, such as Ucareo, in the Purépecha territory in West Mexico. The findings suggest a sophisticated economy that relied not only on conquest but on active long-distance trade, even with rival polities.

“Although the Mexicas preferred green obsidian, the high diversity of obsidian types, mainly in the form of non-ritual artifacts, suggests that obsidian tools from multiple sources reached the capital of the Empire through market instead of direct acquisition in the outcrop,” said lead author Diego Matadamas-Gomora, a PhD candidate in Tulane’s Department of Anthropology. “By studying where this material came from, we can explore the movement of goods across Mesoamerica.”

The analysis showed that nearly 90% of the obsidian artifacts in the sample were made with Sierra de Pachuca obsidian – prized for its green hue and symbolic connection to the mythical city of Tollan. Almost all the ceremonial artifacts found inside buried offerings at the Templo Mayor were made with this type of obsidian, including miniature weapons, jewelry and inlays for sculptures.

A smaller but significant portion of the obsidian came from places like Otumba, Tulancingo, Ucareo and El Paraíso, some of which lay outside the control of the Mexica Empire. These materials were more commonly used for tool production and found in the construction fill, indicating that these obsidian types were available to the general population through local markets rather than being tightly controlled by the state.

The study also tracked how obsidian use shifted over time, from the city’s earliest phases around 1375 CE through its fall in 1520 CE.

During the empire’s early phases, more diversity in obsidian sources appeared in both ritual and everyday objects. After the Mexica consolidated power around 1430 CE, obsidian for ritual purposes became almost exclusively sourced from Sierra de Pachuca, suggesting growing religious standardization and centralized control.

“This kind of compositional analysis allows us to trace how imperial expansion, political alliances and trade networks evolved over time,” Matadamas-Gomora said.

The research was made possible through a partnership between Tulane and Mexico’s Proyecto Templo Mayor of the National Institute of Anthropology and History (INAH), with artifacts analyzed using portable X-ray fluorescence (pXRF), a non-destructive method that identifies the geochemical fingerprint of each artifact.

“This work not only highlights the Mexica Empire’s reach and complexity but also demonstrates how the archaeological sciences can be leveraged to study ancient objects and what they can tell us about past cultural practices,” said study co-author Jason Nesbitt, an associate professor in Tulane’s Anthropology Department.

This publication was partially funded by Tulane’s Supporting Impactful Publications (SIP) Program. It is co-authored by Tulane researchers Nesbitt, Julia Sjödahl and Tatsuya Murakami, and INAH researchers Leonardo López Luján, Rodolfo Aguilar Tapia and Alejandro Pastrana.

---

Journal

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2500095122 

Ancient Andes society used hallucinogens to strengthen social order

Two thousand years before the Inca empire dominated the Andes, a lesser-known society known as the Chavín Phenomenon shared common art, architecture, and materials throughout modern-day Peru. Through agricultural innovations, craft production, and trade, Chavín shaped a growing social order and laid the foundations for hierarchical society among the high peaks.

But one of their most powerful tools wasn’t farming. It was access to altered states of consciousness.

That’s according to a new study that uncovered the earliest-known direct evidence of the use of psychoactive plants in the Peruvian Andes. A team of archaeologists from the University of Florida, Stanford University and South American institutions discovered ancient snuff tubes carved from hollow bones at the heart of monumental stone structures at Chavín de Huántar, a prehistoric ceremonial site in the mountains Peru.

By conducting chemical and microscopic analyses of the snuff tubes, the researchers revealed traces of nicotine from wild relatives of tobacco and vilca bean residue, a hallucinogen related to DMT. The leaders, it seems, wielded these substances not just for personal visions but to reinforce their authority.

Unlike communal hallucinogenic use common in other ancient cultures, Chavín’s rituals were exclusive. Archaeologists discovered the snuff tubes in private chambers within massive stone structures that held only a handful of participants at a time, creating an air of mystique and control.

“Taking psychoactives was not just about seeing visions. It was part of a tightly controlled ritual, likely reserved for a select few, reinforcing the social hierarchy,” said Daniel Contreras, Ph.D., an anthropological archaeologist at UF and co-author of the new study that revealed these rituals at Chavín.

These experiences were likely profound, even terrifying. To those who inhaled, the supernatural might have felt like a force beyond comprehension. And that was precisely the point. By controlling access to these altered states, Chavín’s rulers established a potent ideology and convinced their people that their leadership was intertwined with mystical power and part of the natural order.

“The supernatural world isn’t necessarily friendly, but it’s powerful,” Contreras said. “These rituals, often enhanced by psychoactives, were compelling, transformative experiences that reinforced belief systems and social structures.”

Contreras has spent nearly thirty years studying the site as part of a team led by John Rick, Ph.D, professor emeritus at Stanford University. The team argue that these ceremonies were pivotal in shaping early class structures. Unlike forced labor societies, Chavín’s builders likely believed in the grandeur of the monuments they were constructing, persuaded by these immersive rituals.

Those rituals extended beyond the use of psychedelics. Archaeologists have also uncovered trumpets made from conch shells and chambers seemingly designed to enhance the awe-inducing musical performances.

"One of the ways that inequality was justified or naturalized was through ideology — through the creation of impressive ceremonial experiences that made people believe this whole project was a good idea,” Contreras said.

Their study was published this week in the Proceedings of the National Academy of Sciences.

The findings help solve a century-old mystery about this site, located at an elevation of 10,000 feet. Since its first excavation over a hundred years ago, Chavín has been seen as related to both earlier, more egalitarian societies and the mountain-spanning empires ruled by powerful elites that came later.

Controlled access to mystical experiences helps explain this major social transition, a finding only made possible by decades of intense excavations and advanced analytical methods.

“It’s exciting that ongoing excavations can be combined with cutting-edge archaeological science techniques to get us closer to understanding what it was like to live at this site,” Contreras said.

---

Journal

Proceedings of the National Academy of Sciences