Lending A Hairy Hand

Chimpanzees are similar to humans, even when it comes to helping.

- Galadriel Watson

Helping other people is super nice—but also sometimes selfish. Today at lunch I may give you a handful of my pretzels, secretly hoping that tomorrow you’ll give me a bite of your chocolate bar. Or maybe I volunteer to play tuba for the school band knowing I’ll get to go on a cool trip. Helping others out feels great—but would it be as wonderful if I wasn’t going to benefit too?

Let’s ask the chimps. Chimpanzees are among humans’ closest relatives, and they’ve also been known to help each other. They sometimes hunt together, share food, or groom each other. But what if the favor won’t be returned or—worse yet—there’s an actual cost to helping out? Would a chimp still do it?

THANKS, TAI

Meet Tai. She’s a chimp who lives in the Wolfgang Köhler Primate Research Center in Germany. She was trained to help out other chimps, so researchers could see if those chimps would help her out in return.

In one version of the experiment, Tai didn’t do much of anything. She stood outside a small metal booth. On the opposite side of the booth stood another chimp. For some of the trials, this was a chimp named Kofi. Inside the booth were two choices of food. By pulling on various ropes, Kofi could give himself four pieces of food and give Tai none or give both Tai and himself three pieces of food.

Not surprisingly, Kofi almost always picked the selfish option and took the four pieces of food for himself.

Then researchers had Tai take a chance. She got first choice of the food bowls. But rather than selecting food, she pulled on a rope that opened a latch. This allowed Kofi to decide who got what food instead. Tai was trained to take this action, but Kofi didn’t know that. To him, it looked like Tai had taken a big risk—perhaps not getting any food at all—by letting Kofi pick.