New research on mice at the University of Wisconsin-Madison and the Oregon Health and Science University has concluded that the ability to empathize with others is at least somewhat determined by genes
And the researchers say that understanding empathy in mice could lead to crucial discoveries about human psychosocial disorders, including autism, schizophrenia, addiction and depression. The new research appears in the Public Library of Science ONE journal.
"The core of empathy is being able to have an emotional experience and share that experience with another," said UW-Madison graduate student Jules Panksepp in a release announcing the findings. "We are basically trying to deconstruct empathy into smaller functional units that make it more accessible to biological research."
In the experiments, a mouse observed another mouse in a test chamber, and was trained to associate a 30-second sound with a mild foot shock. When shocked, the test mouse emitted a short distress signal or squeak. Even though observers from a sociable mouse strain had no knowledge of the foot shock, they correlated the distress calls with something negative: When they were later placed in the test chamber themselves, they showed clear physiological signs of aversion (freezing in place, for instance) even though they didn't receive a shock.
In contrast, observer mice from a less social-friendly strain - who are less likely to seek out companions -- showed no response to the tone when they were placed in the test chamber.
The researchers say the differences in behavior between the two mice strains prove there is a genetic basis to the ability to recognize and act on another's emotions. And while pet owners will eagerly testify that their dogs and cats pick up on the emotional cues around them, this "empathy effect" has not been demonstrated in a scientific context until now.
"Deficits in empathy are frequently discussed in the context of psychiatric disorders like autism. We think that by coming up with a simplified model of it in a mouse, we're probably getting closer to modeling symptoms of human disorders," Panksepp said.