As social creatures, we subconsciously match moods with those around us—and not just when a cranky supervisor darkens your day (Editor’s Note: Is it something I said?). The scientific term for the spread of feelings is “emotional contagion,” a term that may feel particularly appropriate when it comes to grumpiness. But as is so often the case with human psychology, this very human behavior does not appear to be unique to our species.
Studying emotions and their contagious nature in other animals can be tricky. Relying on outward displays runs the risk of conflating a simple emotion with some overt rowdiness that makes it visible. Getting at that underlying emotion requires understanding how critters act in varying moods. A team led by the University of Vienna’s Jessie Adriaense tried to do that