| Can rats display empathy by alleviating the suffering of an unrelated rat? To find out, psychologists Inbal Ben-Ami Bartal, Jean Decety, and Peggy Mason at the University of Chicago tested whether rats would rescue a trapped cagemate without any obvious reward. The group found that rats would release trapped cagemates from restrainers, but ignored empty restrainers or those containing only a toy rat. In trials with chocolate as a distraction, the rats would free their trapped cagemate before sharing the chocolate, a preferred rat treat. In the accompanying video, paper author Peggy Mason narrates several runs of the experiment. www.sciencemag.org |