Three males groom together in a chain — Likizo (a younger male) grooms Big Brown (an older male), who grooms Lanjo (another younger male). Photo: John Lower Source: Havard Gazette |
Despite the denial of Creationists, humans are very like their closest relatives, the chimpanzees in so many way, and not just physical, physiological and genetic. Our psychology is similar too, as this latest finding shows.
A team of psychologists and primatologists from the Harvard Department of Human Evolutionary Biology has shown that chimpanzees, Pan troglodytes, like humans, tend to be increasing selective in their friendships as they age. Their findings are published today in Science.
It had been thought that this tendency was unique to humans and stemmed from our sense of our own mortality (itself believed to be a uniquely human trait). However, detailed observation has shown that aging chimpanzees also show the same selectivity in their friendship, tending to favour those they know and trust and with whom there has been little history of animosity.