Harappan civilization, or the Indus Valley civilization, developed in the middle of the third millennium BC, at the same time as contemporaneous civilizations in Egypt and Mesopotamia. It stretched over a million square kilometers of what is now Pakistan and India.
The city of Harappa and the city of Mohenjo-Daro – the greatest achievements of this culture – are well known for their impressive, organized layout.
Recent excavations have demonstrated that the cities grew rapidly from 2200-1900 BC, when they were largely abandoned.
“The collapse of the Indus Civilization and the reorganization of its human population has been controversial for a long time,” said Dr Robbins Schug of Appalachian State University, who is the lead author of the study appearing in the open-access journal PLoS ONE.
Climate, economic, and social changes all played a role in the process of urbanization and collapse, but little was known about how these changes affected the human population.
Dr Schug and her colleagues examined evidence for trauma and infectious disease in the human skeletal remains from three burial areas at the city of Harappa. Their findings counter longstanding claims that the Harappan civilization developed as a peaceful, cooperative, and egalitarian state-level society, without social differentiation, hierarchy, or differences in access to basic resources.
The results suggest instead that some communities at Harappa faced more significant impacts than others from climate and socio-economic strains, particularly the socially disadvantaged or marginalized communities who are most vulnerable to violence and disease. This pattern is expected in strongly socially differentiated, hierarchical but weakly controlled societies facing resource stress.
The study adds to the growing body of research about the character of Harappan society and the nature of its collapse.
“Early research had proposed that ecological factors were the cause of the demise, but there wasn’t much paleo-environmental evidence to confirm those theories. In the past few decades, there have been refinements to the available techniques for reconstructing paleo-environments and burgeoning interest in this field,” Dr Schug said.