Mice, Empathy and Animal Experimentation

Much ink has been spilled about the recent paper in Science documenting empathy in mice. The experiment was rather simple. The scientists noticed that mice given a painful injection displayed increased writhing behavior (a reflexive response to pain) in the presence of cagemates who had also been injected. Furthermore, the writhing increased the longer the paired rats had previously been caged together. If the mouse saw their friend get poked with a needle then their own injection seemed to hurt even more.

I tend to agree with Jake over at Pure Pedantry, who argued that "The question of whether mice have empathy comes down to how the authors are choosing to define empathy." In other words, this experiment is about words. The experiment wouldn't be nearly as interesting if the scientists had used a less resonant adjective. For humans, empathy has specific connotations, and seems hopelessly entangled with other subjective states like compassion, kindness, and theory of mind. Using an inexact word like empathy implies that the scientists can somehow understand what these mice are thinking or feeling. Of course, they can't. All they did was quantify writhing. I'm afraid the ambiguities of language make this experiment seem more profound than it is.

Which leads me to my second point. I generally have little sympathy for animal rights activists, but this experiment struck me as needlessly cruel. After all, it was all about inducing and measuring pain. Furthermore, if the scientists are right and mice really do have empathy, then it seems this experiment was even more unjustifiable. I'm all in favor of animal experimentation if it involves medical research or important basic science. (As a former tech, I've sacrificed my fair share of mice.) Unfortunately, I'm not sure that this kind of semantic science is worth the suffering of rodents.