In humans, we are used to believe that females are more empathic than males. Exploring sex differences in animal models has been identified as an urgent need in animal research. Using a paradigm in which a rat witnesses another in distress, the groups of Christian Keysers and Valeria Gazzola measured how sensitive male and female rats were to the distress of a conspecific of the same sex.
In a paper published in Scientific Report, they show that female and male rats actually demonstrated the same level of sensitivity to the distress of others. More specifically, female rats showed less freezing than male rats when they are in distress, but female observers witnessing a female rat showing X% freezing froze as much as a male rat observing a male showing X% freezing. This finding challenges the notion that sensitivity to the distress of others derives from maternal care mechanisms, and supports a more general function for emotional contagion in social animals.