A new study argues that betrayals of trust could be the “missing link” to explain the rapid spread of humans around the world in the past 100,000 years. Broken trust and a sense of betrayal led early humans to travel in distant, risky and inhospitable areas across the world, despite stable environmental conditions in their regions.

An archaeologist at the University of York says that both population increase and ecological changes cannot provide a significant explanation of the patterns of human movement into new regions. The study shows that moral disputes might have motivated early humans to put distance between them and their rivals.

Dr Penny Spikins, from the Department of Archaeology, said that before human dispersals, movement of archaic humans was significantly slow and largely governed by environmental events like population increases or ecological changes.

As the population grows, people tend to express commitments to others for their survival, and human groups became more motivated to determine and punish those who cheat, she suggests.

"Moral conflicts provoke substantial mobility -- the furious ex ally, mate or whole group, with a poisoned spear or projectile intent on seeking revenge or justice, are a strong motivation to get away, and to take almost any risk to do so,” Spikins said.

Early human ancestors, such as hominin, tend to dwell in specific environments like grasslands and open woodland. The species of Homo erectus travelled from Africa to Asia about 1.6 million years ago because of the need to find more large scale grasslands, while Neanderthals live in cold and arid parts of Europe.

Environmental and climatic barriers often push these archaic species to find new settlement, Spikins said. However, after 100,000 years, modern human populations tend to settle in distant, risky and inhospitable areas.

Spikins, a senior lecturer in the Archaeology of Human Origins, noted that the global dispersal was not inhibited by any biogeographical barriers. Humans settled in deserts, jungles and in cold regions of Northern Europe, and even crossed the sea to reach Australia and the Pacific islands.

The study, published in Open Quaternary, argues that betrayals of trust because of moral disputes could be a significant reason for risky dispersals in unwelcoming environments. People were motivated to travel due to the desire to avoid harm from disgruntled former friends and allies.

"Active colonisations of and through hazardous terrain are difficult to explain through immediate pragmatic choices. But they become easier to explain through the rise of the strong motivations to harm others even at one's own expense which widespread emotional commitments bring,” Spikins said.

"While we view the global dispersal of our species as a symbol of our success, part of the motivations for such movements reflect a darker, though no less 'collaborative', side to human nature."

Contact the writer at feedback@ibtimes.com.au or tell us what you think below

RELATED STORIES