Chimpanzees may be more generous than we thought.
Chimps spontaneously displaying empathy by consoling each other after fights and sharing food has been documented by scientists. However, altruistic behavior thought to be unique to humans was shown in previous research to only occur when the chimps were tricked or pressured, the Daily Mail reports.
A new report has found they are more giving than previous studies have credited them for. "Spontaneous Prosocial Choice By Chimpanzees," published in Proceedings of the National Academy of Sciences, reports that chimpanzees are as co-operative as their human cousins, particularly when their partners are patient.
Study leader Dr. Horner told The New York Times the study suggests that rather than altruism being a behavior unique to humans, it is the number of instances in comparison to other mammals that is different.
"We were excited to find female after female [chimpanzee] chose the option that gave both her and her partner food," Dr. Horner told the Daily Mail.
The study found the chimps were much less likely to share the food if their partner kicked up a fuss.
Dr. Horner told LiveScience: "For me, the most important finding is that like us, chimpanzees take into account the needs and wishes of others."
Researcher Frans de Waal said empathy had also been found in capuchin monkeys, marmosets and tamarins, and he expected to find it in dogs and rats as well.
"Since empathy is an old mammalian trait, there is no reason why the sort of altruism we describe should be unique for the primates," de Waal told Discovery News.
Not everyone supports the findings. The New York Times reports that Michael Tomasello at the Max Planck Institute feels the study is poorly designed. Having conducted his own experiment, he came to a different conclusion: “Chimps help others, but what they do not do is give up food themselves so others can have it,” he said. “So they are prosocial when it is not costly, but when it is, not so much.”
An increasing number of studies are showing that other animals share many similar traits to humans. For example, this year, studies have shown that monkeys doubt themselves, and they also show regret and disappointment, just like humans.