New study reveals harsh realities of childhood in the pre-Columbian Andes

Dr. Luiz Pezo-Lanfranco and his colleagues have published a study on child mortality at the Quebrada Chupacigarro Cemetery (QCC) in the International Journal of Osteoarchaeology.

They found that individuals buried within the cemetery showed a high prevalence of health-disease processes likely linked to high population density, poor sanitation, and nutritional deficiencies during the transition from the Middle Formative to the Late Formative Period (500–400 BC) in the Central Andes.

During this transitional period, theocratic governments and large ceremonial centers were abandoned in favor of secular governments, with populations relocating to clustered settlements atop defensive hilltops and fortresses.

It is within this setting that the QCC was used. Located atop the slopes of the Cerro Mulato, along the left bank of the Supe River, this cemetery was first discovered and excavated in 2011.

The human remains included 67 exceptionally preserved human burials, 47 of which represented children below the age of eight.

According to Pezo-Lanfranco, QCC provided a unique opportunity to study the bioarchaeology of children during the Formative Period. "The idea of studying the bioarchaeology of children from this period arose as a matter of opportunity. This is one of the few collections from that specific period (500–400 BCE) and one of the few fully excavated cemeteries from the Formative Period (3000–1 BCE)."

"Children have historically been marginalized in bioarchaeological research for several reasons, such as poor preservation of their skeletons due to their inherent fragility, differential burial practices between adults and preadults, or anticivilization of this group by the archaeologists," said Pezo-Lanfranco.

"Little is known about the paleopathology of preadults in prehistoric Peru, and this cemetery provided an interesting opportunity to examine the quality of life of these children."

Analysis of the remains revealed various bone markers related to health-disease processes. These included cribra orbitalia (CO, eye-socket lesions often linked to anemia), porotic hyperostosis (PH, skull bone porosity linked to chronic anemia), periosteal reactions (PR, new bone formation caused by infection or inflammation), linear enamel hypoplasia (LEH, arrested tooth growth caused by periods of intense stress or trauma).

According to Pezo-Lanfranco, "What we observe in QCC children is anemia, which was endemic in prehistoric Peru and remains so in present times, strongly linked to early mortality.

"My interpretation is that those who survived into adulthood—who rarely show signs of anemia or only exhibit healed lesions—also suffered from anemia and other stressors (such as infections and severe malnutrition) but were able to survive due to factors that remain unclear. Those individuals who overcame these stressors by around 3.5 years of age (as estimated by LEH) tended to survive into adulthood."

The study found that around 85% of bones belonging to individuals below eight years of age had signs of PR, while almost half of those that survived into childhood (aged 25) had LEH, indicating these children were subject to chronic and severe inflammations, infection, anemia, and stress.

Pezo-Lanfranco believes these health-related issues and high infant mortality were likely caused by malnutrition, coupled with poor sanitation and high population densities.

"High population density, lack of sanitation, and nutritional deficiencies are the most clearly related factors to this vulnerability. Imagine a poor community threatened by an apparently inter-community conflict, with high population density, malnourished adults (mothers), and a large number of infants and children demanding food.

"Malnourished children, exposed to infectious diseases and lacking proper sanitation, would have been extremely vulnerable to any additional stressors."

It is possible that environmental factors such as events related to ENSO (El Niño and Southern Oscillation) led to irregular water flow, floods, and landslides. These would disrupt regular food and water supplies, leading to people congregating in areas where these resources are more readily available.

"The Supe River has a highly irregular flow, and it is possible that these people drank from springs or directly from the river, which may have been contaminated by upstream settlements with poor sanitation.

"A previous study has detected individuals infected with parasites associated with the use of contaminated water for crop irrigation. It is highly likely that the children in this farming community were exposed to gastrointestinal parasites, water scarcity, contaminated water, and intestinal infections, which could lead to potentially fatal diarrhea," explained Pezo-Lanfranco.

Many questions remain, and Pezo-Lanfranco hopes further research will provide answers.

"We now have considerable information about QCC. However, many other questions arise … One of our key questions is whether this high childhood morbidity scenario corresponds to the context of structural violence specific to QCC and the Middle-Late Formative transition, or if it represents a pattern recurring across the Andes over time. If so, when did this pattern emerge?"

"We are really interested in determining whether this phenomenon already occurred in earlier times, such as during the flourishing of the Caral Civilization (3000–1800 BCE) in the Supe Valley, subsequent periods, or during the Middle Formative, when the Chavín cult was hegemonic.

"We also want to explore whether this pattern was exclusive to marginal and rural populations like QCC or if it also occurred among elites or richer settlements, particularly in the early stages of Andean civilization."

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