Washington, Feb 9 : Unlike chimpanzees, African Bonobos have an inborn quality of sharing, reveals a new study.

While chimps will share as youngsters, they turn notorious as they grow old.

In several experiments to measure food-sharing and social inhibition among chimps and Bonobos living in African sanctuaries, Duke and Harvard researchers say these behavioural differences may be rooted in developmental patterns that portray something about the historical lifestyles of these two closely related apes.

When compared with chimps, bonobos seem to be living in "a sort of Peter Pan world," said Brian Hare, an assistant professor of evolutionary anthropology at Duke University, who participated in both studies.

"They never grow up, and they share," he added.

The researchers believe that gentler ape"s behaviour has been shaped by the relative abundance of their environment.

Living south of the Congo River, where food is more plentiful, bonobos don"t compete with gorillas for food as chimps have to, and they don"t have to compete much with each other either.

The cognitive tests performed on the captive animals revealed Bonobos shared like juveniles even after they reached adulthood.

"It seems like some of these adult differences might actually derive from developmental differences," said Harvard graduate student Victoria Wobber, who is the lead author on one of the papers. "Evolution has been acting on the development of their cognition."

During the study, paired animals at the Tchimpounga Sanctuary in the Republic of the Congo were put into an enclosure with some food.

Younger chimps were found to be quite similar to young bonobos in their willingness to share food, but the chimps become less willing to share when they"re older.

The second set of sharing experiments, researchers at the Lola ya Bonobo sanctuary near Kinshasa, Democratic Republic of Congo gave bonobos an opportunity to have all of a food pile to themselves while a fellow bonobo watched helplessly from behind a gate.

Instead, the subjects universally preferred to open the gate and let their friends share. Their friends weren"t even begging or carrying on.

The findings appear in journal Current Biology.