Twelve chimpanzees were used in the experiments. Six of them were mother-offspring pairs. The scientists claim that the tests show the chimpanzees, especially the mother-offspring pairs, helping each other selflessly.

 

“As a difference between the humans and chimpanzees, it is considered humans act spontaneously in an altruistic(无私的) way, but this result poses a question.”

 

Yamamoto said that in some of the experiments, chimps were filmed passing sticks or straws to other chimps. The sticks were then used to reach straws otherwise out of reach or in the case of the passed straw to drink juice.

 

Yamamoto said the chimps were trained to use sticks to drag straws placed out of reach, and to use straws to drink juice. But he claimed the transferring of the sticks or the straws to other chimps was not trained.

 

The Institute reported the pairs of primates(灵长目动物) passed the items to each other 59% of the time, even though the action did not benefit both of them. Yamamoto noted that the passing of items occurred more often when a chimp appeared to make a request for the straw or stick. In those instances, he said transfers were made 75% of the time.

 

One leading animal behavior researcher believes these results show chimps and humans are more alike than previously thought.

 

“Although chimpanzees and humans are almost the same animals if you look at the composition of DNA, we normally think that humans create higher social systems by helping each other. So we normally think there is a wide gap between the humans and chimps. But the results of this experience filled the gap between the two species. The results show that chimps also have humanity in their behavior. ”

 

It’s not the first time researchers have claimed to witness altruism(利他主义) in chimps. German researchers at the Max Planck Institute for Evolutionary Anthropology reported similar results in 2007.