Environmental pressures may have led humans to become more tolerant and friendly of each other, as the need to share food and raw materials became mutually beneficial, a new study suggests.
This behavior was not an inevitable natural progression, but subjected to ecological pressures, concludes the study of the University of York.
Humans have a remarkable ability to care for people far outside of their own kinship or a local group. While most other animals tend to be defensive towards those of other groups, our natural tolerance today allows us to collaborate on a global scale, as seen with trade or international relief efforts to provide assistance in the event of natural disasters.
Using computer simulations of several thousand individuals gathering resources for their group and interacting with individuals from other groups, the research team attempted to establish what key evolutionary pressures may have induced human intergroup tolerance. .
The study suggests that this may have started when humans started to leave Africa and during a period of increasingly harsh and variable environments.
The study looked at the period 300,000 to 30,000 years ago, when archaeological evidence indicated greater mobility and more frequent interactions between different groups. In particular, it is a period when there is movement of commodities over much longer distances and between groups.
The researchers found that populations who shared resources were more likely to succeed and survive harsh environments, where extinctions occur, than populations who did not share borders.
However, in resource-rich environments sharing was less beneficial and in extremely harsh environments populations are too small for sharing to be feasible.
Penny Spikins, professor of human origins archeology at the University of York, said: “That our study demonstrates the importance of tolerance for human success is perhaps surprising, especially when we often think of prehistory like a time of competition, however we have seen that in situations where people with surpluses share across borders with those in need, everyone benefits in the long run. ”
Dr Jennifer C. French, Senior Lecturer in Paleolithic Archeology at the University of Liverpool, added: “The results of our study also have important implications for wider debates on increasing examples of innovation and higher rates of cultural evolution that occurred during this period.
“They help explain previously enigmatic changes in archaeological records between 300,000 and 30,000 years ago.”
The study is published in the Journal of Archaeological Method and Theory.