by Tara Green
(NaturalNews) An animal whose very name is often used as an insult may harbor more "human" traits like compassion than previously suspected. A recent study by University of Chicago researchers suggests that rats are capable of behavior which seems based on empathy for others of their kind.
Arguments against animal testing tend to center on those animals most like us, such as the great apes, or on animals humans frequently keep as pets like cats and dogs. Meanwhile, arguments for animal testing often center on the notion of animals as dumb beasts operating solely on instinct, unlike the finely tuned higher impulses of the human species. Yet rats in the recent study, published in the December 9, 2011 issue of the journal Science, went out of their way to free another rat that was trapped.
Psychologists at the University of Chicago conducted a series of experiments in which they put one rat inside a clear cage which could only be sprung from the outside. They left another rat to roam free outside the cage for an hour at a time. The free rat initially circled the cage, attempting to dig beneath it or bite through it. After several times of seeing its trapped cohort, the roaming rat learned how to open the cage and free the other rat. "It's very obvious that it is intentional," says study coauthor Inbal Ben-Ami Bartal. "They walk right up to the door and open the door." After the trapped rat was freed, both animals engaged in excited running.
The experiment was designed to determine whether the rats would act merely from curiosity about the mechanism of the cage. Rats who encountered an empty cage were less likely to learn to operate its latch. Twenty-three out of 30 rats who saw a trapped rat in the cage learned to open the cage, but only 5 of the 40 rats who saw an empty cage learned to work the mechanism. Rats reacted to seeing a stuffed animal in the cage in the same way as they did to seeing an empty cage.
Choosing kindness over chocolate
The rats received no reward for rescuing their caged cohorts. In one part of the experiment, food was actually offered as an alternative. Roaming rats were presented with two cages, one with a trapped rat another containing chocolate chips. "These rats adore their chocolate," Bartal notes. Researchers were surprised to observe that the rats were equally likely to free their fellow rodent as they were to open the cage with the chocolate.
Not only that, the rats engaged in sharing. "The most shocking thing is they left some of the chocolate for the other rat," Bartal says. The rescuer rats left some chocolate for their newly freed fellow rodents in more than half of the trials. "It's not like they missed a chocolate," Bartal says. "They actually carried it out of the restrainer sometimes but did not eat it."
Gender may play a role in rat behavior, according to the researchers. Study author Peggy Mason noted that female rats displayed more empathy than males. All six females in the study freed a trapped rat; 17 of the 24 males did so.
The researchers say the study demonstrates that pro-social empathy is not limited to humans and primates. "There are a lot of ideas in the literature showing that empathy is not unique to humans, and it has been well demonstrated in apes, but in rodents it was not very clear," said Jean Decety, a professor of psychology and psychiatry at the University of Chicago. "We put together in one series of experiments evidence of helping behavior based on empathy in rodents, and that's really the first time it's been seen."