An international team of researchers has found that the inhabitants of the Neolithic settlement Çatalhöyük (7100-5950 BCE) experienced overcrowding, infectious diseases, violence and environmental problems. The research was published in the Proceedings of the National Academy of Sciences.
Çatalhöyük began as a small settlement about 7100 BCE, likely consisting of a few mud-brick houses in what archaeologists call the Early period.
It grew to its peak in the Middle period of 6700 to 6500 BCE, before the population declined rapidly in the Late period. The settlement was abandoned about 5950 BCE.
Ohio State University’s Professor Clark Spencer Larsen and colleagues analyzed a chemical signature in the bones of Çatalhöyük’s residents — called stable carbon isotope ratios — to determine that they ate a diet heavy on wheat, barley and rye, along with a range of non-domesticated plants.
Stable nitrogen isotope ratios were used to document protein in their diets, which came from sheep, goats and non-domesticated animals.
Domesticated cattle were introduced in the Late period, but sheep were always the most important domesticated animal in their diets.
“They were farming and keeping animals as soon as they set up the community, but they were intensifying their efforts as the population expanded. The grain-heavy diet meant that some residents soon developed tooth decay — one of the so-called diseases of civilization,” Proffesor Larsen said.
The results showed that about 10-13% of teeth of adults found at the site showed evidence of dental cavities.
“Changes over time in the shape of leg bone cross-sections showed that community members in the Late period of Çatalhöyük walked significantly more than early residents. That suggests residents had to move farming and grazing further from the community as time went on,” Proffesor Larsen said.
“We believe that environmental degradation and climate change forced community members to move further away from the settlement to farm and to find supplies like firewood. That contributed to the ultimate demise of Çatalhöyük.”
The team also found that Çatalhöyük’s residents suffered from a high infection rate, most likely due to crowding and poor hygiene.
Up to one-third of remains from the Early period show evidence of infections on their bones.
During its peak in population (3,500-8,000 people), houses were built like apartments with no space between them — residents came and left through ladders to the roofs of the houses.
Excavations showed that interior walls and floors were re-plastered many times with clay. And while the residents kept their floors mostly debris-free, analysis of house walls and floors showed traces of animal and human fecal matter.
“They are living in very crowded conditions, with trash pits and animal pens right next to some of their homes. So there is a whole host of sanitation issues that could contribute to the spread of infectious diseases,” Professor Larsen said.
“The crowded conditions in Çatalhöyük may have also contributed to high levels of violence between residents.”
In a sample of 93 skulls from Çatalhöyük, more than one-fourth — 25 individuals — showed evidence of healed fractures. And 12 of them had been victimized more than once, with two to five injuries over a period of time.
The shape of the lesions suggested that blows to the head from hard, round objects caused them — and clay balls of the right size and shape were also found at the site.
More than half of the victims were women (13 women, 10 men). And most of the injuries were on the top or back of their heads, suggesting the victims were not facing their assailants when struck.
“We found an increase in cranial injuries during the Middle period, when the population was largest and most dense,” Professor Larsen said.
“An argument could be made that overcrowding led to elevated stress and conflict within the community.”
Most people were buried in pits that had been dug into the floors of houses, and researchers believe they were interred under the homes in which they lived. That led to an unexpected finding: most members of a household were not biologically related.
“The morphology of teeth are highly genetically controlled. People who are related show similar variations in the crowns of their teeth and we didn’t find that in people buried in the same houses,” Professor Larsen said.
“More research is needed to determine the relations of people who lived together in Çatalhöyük. It is still kind of a mystery.”