Pier Francesco Ferrari; (inset, left) Elizabetta Palagi

ScienceShot: Monkey Smiles Are Contagious

Believe it or not, the gelada monkeys (Theropithecus gelada) on the right may be sharing a good laugh—and possibly the emotions that go along with it. Previously, only humans and orangutans had been shown to quickly and involuntarily mimic the facial expressions of their companions, an ability that seems to be linked to empathy. After spending months observing every playful interaction among the gelada population at Germany's NaturZoo, scientists are ready to add another, more distantly related species to that list. Geladas of all ages were more likely to mimic the play faces of their companions within 1 second of seeing them than they were to respond with a different kind of expression, according to a paper published by the team this week in Scientific Reports. What's more, the fastest and most frequent mimicry responses occurred between mothers and their infant offspring, like the pair pictured on the left. More research is required to determine if geladas are sharing emotional states in addition to facial expressions, but the team suggests that studying the quantity and quality of these mother-child interactions could provide a way forward.

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