Rats Remember Acts Of Kindness: For The First Time, Direct Reciprocation Observed In The Animal Kingdom

For the first time, scientists have observed the act of direct reciprocation in the animal kingdom. Rats, scientists claim, note and remember acts of kindness bestowed upon them by other acts and even treat their benefactors accordingly.

Rats have earlier proven themselves to be great at trading stocks. They accomplished the feat by observing and remembering patterns. Similarly, a newly conducted observational study proved that rats not only remember who has been good to them, they will return the favor too. In experiments, Norwegian rats were most helpful to individuals that had previously helped them. At the onset, scientists hypothesized the behavior could be an attempt to ensure future assistance or favors.

Rats have been known to cooperate and assist one another for quite some time, but rewarding another rat for no immediate gain was never observed. In fact, a rat rewarding a fellow rat for help — an act called direct reciprocation — is certainly a first among non-humans, shared study co-author Michael Taborsky, a behavioral ecologist at the University of Bern in Switzerland.

The study was based on the behavior of captive female Norwegian rats. Scientists knew these rats tolerated carrots, but enjoyed bananas. In the experiment, each of a pair of rat helpers could deliver one of these tidbits to a rat in another enclosure by pulling on a stick. Eventually, the receiving rat recognized each helper as either a high-quality helper (if it delivered bananas) or a low-quality helper (if it delivered carrots).

When their places were switched, the rats that had been given bananas generally received food far more quickly and more often than their carrot-giving colleagues. Similarly, those who had dished-out carrots got food much less often than those who served bananas.

Though researchers admit more study is required to truly establish if rats really were rewarding helpers for their generosity, researcher Taborsky maintains rats are making a simple association.

“Two elements are involved: recognizing an individual, and responding to the quality of service. The latter is evident from previously known behavior — rats will flock to good feeding spots, for example. And recognition is widely documented in many species, including rats.”

Since Norwegian rats exchange favors, a desire to reward others — and perhaps to ensure more exchanges in the future — “might not be as complex as we think,” points out Taborsky.

However, a few scientists, including Thomas Zentall, feel that the rats may have simply associated the “helper” with the preferred food. But Taborsky argues this isn’t the case since it’s known that rats can tell they’re delivering food to another rat, not themselves.

Rats have proven their smartness on many occasions. Hence their ability to sense an opportunity to please someone in expectation of favors in the future might not be a farfetched notion.

[Image Credit | Brian Johnson]