After the University of Chicago's experiment on empathetic rats made news last year, people from around the world contacted neurobiology professor Peggy Mason to share their anecdotal tales of animals appearing to exhibit compassionate behavior.
A New Jersey biology teacher wrote about what happened after one of his two classroom rats became paralyzed years ago. He said the healthy rat dragged the disabled one to the water bowl and food bowl every day for months until the paralyzed rat died.
A woman told the story of an ant coming to the aid of another ant that was lying flat on its belly. The heroic ant, the woman said, "methodically went around (the disabled ant) pushing up each leg until (it) was standing again."
Mason received accounts of similar acts of benevolence by tortoises, squirrels, mice and more rats, including one that appeared to perfume itself by dabbing on fragrant tulip dust. (Yes, among many species, one's attention to personal hygiene can be considered charitable.)
The rat experiment, which Mason worked on with University of Chicago researchers Inbal Ben-Ami Bartal and Jean Decety, will be featured on the PBS program "NOVA ScienceNOW" on Wednesday night. The installment is called "What Are Animals Thinking?"
It's a fairly controversial question, along with: Are animals indeed contemplative? Do they really exhibit pro-social, or helping, behavior? Some people are loath to believe that humans and animals share traits once thought to be our sole domain.
Last week, I visited the Harvard-trained Mason, 52, in her U. of C. laboratory and watched her pink-tailed, whiskery rodents (Oh my!) roam their cages. We talked about what we can learn from our mammalian friends and how she came to such a fascinating field of study.
The groundbreaking rat experiment took three years to complete and was published in December in the journal Science. During the study, two rats were placed in an enclosure, with one rat cordoned off in a Plexiglas restraining tube. The free rat worked diligently to liberate its trapped cagemate by opening a door, in a display resembling empathy.
In experiment after experiment, the free, selfless rats did so even when they had the option of munching chocolate instead.
"The (free rats) don't open the door if the restrainer is empty or if there is a toy rat inside," said Mason. "They're not doing this for what I call the Mount Everest reason, that is, just because it's there. They do it because they feel sufficiently rewarded to want to do it again."
She said one aspect of the study that didn't get a lot of attention had to do with the door that the rescuing rats had to push open.
Though the door was carefully designed to be neither too easy nor too difficult to nudge, the process of opening a door is still a complex one for rats and took them on average about six days to figure out. Mason said that in the beginning, they would get so frustrated that they would give up.
"We had to make a way for them to realize this was a doable task," she said. "After 40 minutes of them trying, we opened the door at a 45-degree angle. At that point, it gave the free guy hope that the next day he could figure it out."
By the second or third tries, the rats had cracked the code.
When you watch Mason in her lab as she studies her rats — on video surveillance so as not to disturb the science of it all — her face lights up and it's clear that she's at home.
She said that ever since she was a girl growing up in the Washington, D.C., area, she's been drawn to animals and science. Initially, she was smitten by the art of taxidermy, and by age 10 she was helping to teach classes at the Smithsonian.
"I enjoyed it so much that I would pick up roadkill and I would stuff it," she said, laughing. "My brother was into cooking rabbits and we had a big (stand-alone) freezer. Part of it was filled with rabbits and another part with roadkill in bags labeled, 'Don't cook.'"
But as a child she also had seizures and was fascinated by the inner workings of the brain. In graduate school, she decided to focus on neurobiology. She arrived at studying empathy in rats after years of researching how the brain suppresses pain with and without narcotics.
She said one of the most interesting developments in pain research during the past 15 years has been learning, from magnetic resonance imaging, that Person A who is not in pain can view Person B who is in pain, and that can activate the pain region of Person A's brain.
The nonafflicted person wouldn't feel physical distress but would feel — you guessed it — empathy.
Mason said she and her colleagues conducted several experiments that weren't part of the published study.
In trying to figure out how determined the free rats were in their efforts to rescue the trapped rats, researchers learned that rats would travel through water, which they don't particularly care for, but not oil.
Another experiment showed that the mothering styles of rats affected how empathetic their pups would be as adults. Better mothering meant more "caring" rats, and it didn't matter if the mother was a biological mom or a surrogate.
So what does all of this mean for humans?
"What it means is that it is our biological inclination to help another individual in distress," Mason said. "When we choose not to do that — and sometimes that's not a bad thing — we're actively suppressing that inclination to help."
