With a few liberating swipes of their paws, a group of research rats freed trapped labmates and raised anew the possibility that empathy isn't unique to humans and a few extra-smart animals, but is widespread in the animal world.
In a study published in Science, Mason and University of Chicago psychologists Jean Decety and Inbal Ben-Ami Bartal describe their rat empathy-testing apparatus: An enclosure into which pairs of rats were placed, with one roaming free and the other restrained inside a plastic tube. It could only be opened from the outside, which is exactly what the free rats did - again and again and again, seemingly in response to their trapped companions' distress.The Presurfer