By Carl Zimmer
The New York Times
How generous is an ape? It’s a hard question for scientists to tackle, but the answer could tell us a lot about ourselves.
People in every culture can be generous, whether they’re lending a cellphone to an office mate or sharing an antelope haunch with a hungry family.
While it’s easy to dwell on our capacity for war and violence, scientists see our generosity as a remarkable feature of our species. “One of the things that stands out about humans is how helpful we are,” said Christopher Krupenye, a primate behavior researcher at the University of St. Andrews in Scotland.
This generosity may have been crucial to the survival of our early ancestors who lived in small bands of hunter-gatherers.
“When our own attempts to find food are unsuccessful, we rely on others to share food with us — otherwise we starve,” said Jan Engelmann, a researcher at Göttingen University.
To understand the origin of this impulse — known as prosociality — a number of researchers have turned to our closest living relatives. For example, a new study involving bonobo apes suggests that the roots of human generosity run deep, but only came into full flower over the course of the evolution of our species.
Roughly seven million years ago, our lineage split from the ancestors of chimpanzees and their cousin species, bonobos. Chimpanzees and bonobos share a common ancestor that lived about two million years ago.
These two closely related species of apes look almost identical to the untrained eye. But they have evolved some intriguing differences in their behavior, including which objects — food or tools — prompt them to behave with generosity.
Recently, Dr. Krupenye and his colleagues tested the generosity of bonobos that live in the Lola Ya Bonobo sanctuary in the Democratic Republic of Congo.
They proved to be generous — to a point.
Picture: Christopher Smart (book) [Public domain], via Wikimedia Commons