Homicides peaked 4,000 years ago

European archaeologists and historians have turned homicide investigators by peeling back the veil on human conflict thousands of years ago.

While data on homicide and assaults are readily available today, record keeping over the millennia is, unsurprisingly, less extensive. But records may exist in human remains unearthed by scientists over the years.

Writing in Nature Human Behaviour, Professor Joerg Baten from the University of Tübingen, Giacomo Benati from the University of Barcelona and Professor Arkadiusz Sołtysiak from the University of Warsaw have ascertained a high point in historic human conflict by developing a dataset of ancient skeletons from the Middle East.

They studied the remains of more than 3,500 people uncovered in the region from modern-day Turkey around the Mediterranean Sea to Iran from 12,000-400 BCE.

Using skeletons with signs of head trauma or weapon-inflicted wounds, their database quantified injuries by period, geographic location, and cause of injury. 

The scale of lethal aggressions substantially dropped around 3,000 years ago during the transition from the Chalcolithic era into the Bronze Ages. It suggests a peak in human violence during the former, a period from 4,500-3,300 BCE.

This was a period characterised by increasing urbanisation, which would have brought people closer together in growing cities.

“Crowding and rising inequality may have triggered conflicts following appropriation of other groups’ resources resulting in higher interpersonal violence,” the authors suggest.

While this period marked the rise of early nations, the researchers remark “their ability to settle conflicts within their populations was seemingly still quite limited”.

Declines in violence were marked during the Bronze Age transition as proto states shifted into classical societies marked by taxation, militarisation, legal systems and bureaucracy.

Interpersonal violence was noted to increase during the transition to the Iron Age (1,200-590 BCE) as state-based conflicts aided by more sophisticated and cheaper weapons combined with climate-forced migrations and economic decline.

“Security gains – seemingly aided by climate and epidemiological shocks temporarily reducing population pressure – were short-lived and the region witnessed major disruptions across the transition between the Bronze and Iron Ages,” the researchers found.