Chimpanzees that have had positive experiences with humans appear to trust people more than they do baboons and unfamiliar chimps, a new study suggests.
The findings, published in the latest Proceedings of the Royal Society B, indicate that chimpanzees can learn to bond and exhibit empathy for members of another species, such that trust develops even at the subconscious level.
As for what chimps think of kind and caring humans, lead author Matthew Campbell told Discovery News, "I have no doubt that we are different in their minds, but an okay kind of different."
Campbell, a researcher at the Yerkes National Primate Research Center, said that an older female chimp named Tai is so pleased to see co-author Frans de Waal, whom she's known for 20 years, that she excitedly pants, bobs her head and stretches out her hand. All of these are behaviors chimps use when greeting each other.
For the study, Campbell and de Waal used contagious yawning to measure "involuntary empathy" among 19 adult chimps at Yerkes that were all raised by other chimps in captivity.