Why humans started being friendly and tolerant?

Why do we have friends? Of course, we can come up with many answers – favours, emotional support, adventures. But why do humans have friends in general – why did we evolve to need them? Scientists at the University of York think that the leading force between our initial friendliness was environmental pressures.

Humans had to learn to be friendly to improve their chances of survival. Image credit: Sharon & Nikki McCutcheon via Wikimedia (CC BY 2.0)

Humans are incredibly social animals. Our need for social interactions is so great that loneliness is a risk factor for many different health conditions. But not all animals are like that. And human ancestors to our knowledge were not always that friendly. Family is one thing – it satisfied biological needs. But why friends?

Scientists used computer simulations of many thousands of individuals gathering resources for their group and interacting with individuals from other groups. They wanted to see some kind of evolutionary advantage that humans could gain by becoming tolerant to people from other groups. Scientists focused on the period of 300,000 to 30,000 years ago – this time marked increased mobility and new environmental challenges. Scientists say that at those times our ancestors learned to move raw materials over longer distances and between groups. These simulations showed that sharing resources helped humans to survive in harsh environmental conditions. However, for this to work conditions had to be suitable.

In extremely harsh conditions there was not enough resources to share. Meanwhile in resource rich conditions sharing was simply not needed and communication between groups was probably not as intense. This means that some environmental factors invited humans to be more tolerant towards each other, because that was a better survival strategy than relentless competition. Scientists think that this could also help explaining why there were more examples of innovation and cultural evolution during that period – people were communicating and sharing more.

Penny Spikins, one of the authors of the study, said: “That our study demonstrates the importance of tolerance to human success is perhaps surprising, especially when we often think of prehistory as a time of competition, however we have seen that in situations where people with surplus share across borders with those in need everyone benefits in the long term.”

Researching early friendships is very important because they lead to something else – societies. Sticking with your family members exclusively is not possible in every situation. It is not a great choice genetically and in terms of survival in times with limited resources.


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