In some ways, chimps found to behave better than humans

Chimpanzees may be the closest cousins there are to human beings, with the two species sharing 98% of the same DNA, but researchers recently reported one humbling difference: Apes aren’t nearly as nasty and mean-spirited as people are.

“Spitefulness may be a peculiarly human trait,” said Keith Jensen, a Canadian evolutionary biologist who has been looking to see whether human concepts such as fairness and punishment are present in the social organization of another highly socialized species.

In a paper published in July in the Proceedings of the National Academy of Sciences, Jensen and two colleagues argue that chimps are vengeful but not spiteful.

Researchers placed chimps in two facing cages spaced 3 feet apart, with a snack piled on a narrow, wheeled table between them.

One chimp could pull on a rope to bring the table close enough to get the food. But the rope in the other cage allowed the second chimp to collapse the table and spill the food on the floor so neither could reach it.

After the chimps were familiar with the arrangement, researchers set up two scenarios.

In one, the table was close to the chimp with the power to collapse the table -- close enough for the animal to eat the snacks. Invariably, the second chimp would “steal” the table by pulling it to the other side.

“That usually would enrage the chimps who lost the food,” Jensen said. The victimized chimp would punish the thief by collapsing the table and scattering the food out of reach.

The researchers labeled this behavior as vengeance, calling it a positive action in building social relationships because it punishes negative behavior and fosters cooperation that benefits the larger society.

In the second scenario, a human would take away one chimp’s snack and give it to the other. In this case, the first chimp could have spitefully pulled the rope so the second chimp could not have the snack either -- but it did not.

“Spite is kind of interesting because it is altruism’s evil twin,” Jensen said. “Humans can care about making somebody feel better, but we also have the darker side of sometimes wanting to make somebody feel worse.”

Because chimps are closely related genetically to human beings, scientists increasingly are studying their behavior for clues to the origins of human behavior.

“This kind of research is interesting because it makes us [humans] look at ourselves more closely,” Jensen said.