Altruism-On-Demand: I’ll help, but only if you ask nicely…
On Thursday, scientists rescued a dog from the icy waters of the Baltic Sea…In December, a Portland, Maine “secret Santa” gave 100 strangers $100 apiece…And, so far, Americans have donated $29 million to American Red Cross Haiti relief efforts.
Humans are so darn nice. But how exactly did that happen? That’s what scientists at the Primate Research Institute at Kyoto University in Japan are trying to figure out. To gain insight into the evolution of human altruism (a demonstration of unselfish concern for others), the researchers looked at the altruistic behavior—or lack thereof—of chimpanzees.
The scientists placed two chimps into adjacent, transparent booths with a small window between them. Both chimps had access to a juice box (grape juice, of course), but the chimp in the first booth couldn’t drink the juice because the box was anchored to the wall and the chimp in the second booth couldn’t drink the juice because it was just out of reach. To get the juice, the first chimp needed a straw and the second chimp needed a stick.*
In one set of trials (the authors call these the “mismatched” trials) researchers provided the chimp in the anchored-juice-box booth with the stick, and the chimp in the just-out-of-reach-juice booth with the straw. To get at their treats, the chimps would have to get the tool from their neighbor.
The chimps did play nice, handing over the necessary tool to their neighbor in almost 60% of the trials. But seeing their neighbor in need of help only spurred the chimps to offer the necessary tools in 14% of the tool transfers. In most instances (75%), chimps didn’t hand over the tool until the other chimp asked for it—usually by sticking a hairy arm through the window. (In 10% of the successful tool transfers, a chimp stole the tool from its neighbor.).
In a second set of trials, the scientists gave one chimp a juice box either anchored to the wall or just out of reach, while the other chimp had the tool necessary to get the juice. The tool-holder gave the tool to the juice-drinker 90% of the time, 75% of those transfers occurred after the juice-drinker asked for the tool.
This second set of trials led researchers to claim that the transfers were altruism-on-demand and not a form of barter or I’ll-scratch-your-back-if-you-scratch-mine behavior. In theory, the chimp with the tool and no juice had no reason to expect any form of reciprocation when it handed over the tool to the neighbor, which it did at roughly the same rates as in the mismatched trials. (The researchers acknowledged, however, that this still didn’t rule out the fact that the chimps could be collecting IOUs that would get paid back at some future, yet-to-be-determined time.)
Scientists think that altruism-on-demand may be how humans first started helping each other. It’s a fairly efficient way to make sure your help (which usually costs you something in terms of time and effort) is actually needed. But altruism can be a tricky thing to pin down with absolutes. In similar research done at the Planck Institute in Germany, chimps spontaneously offered to help researchers that were clearly struggling to reach a toy or object. No need to ask for help.
So why do chimps consider humans more help-worthy than other chimps? Is it another form of altruism or do they look at humans as providers, and so know which side their bread is buttered on? Couldn’t the long-term IOU be enough to explain why the chimps were willing to help out a neighbor when they had no chance of getting juice for themselves?
As with any study involving a concept such as altruism, with its moral and ethical components, it can be really tough to know exactly what it is you’re observing: a good Samaritan or a savvy businessman.
To watch the full video of the trial, click here.
*The second chimp could pick the juice box up and drink out of it like a cup.
Yamamoto, S., Humle, T., & Tanaka, M. (2009). Chimpanzees Help Each Other upon Request PLoS ONE, 4 (10) DOI: 10.1371/journal.pone.0007416