Bottlenose dolphins exhibit open-mouth expressions, resembling smiles, during play with each other, according to a study in iScience.

A recent study in iScience reveals that bottlenose dolphins exhibit open-mouth expressions, resembling smiles, during play with each other, but not with humans or alone. Researchers recorded 1,288 instances of these "smiles," primarily occurring in dolphin-dolphin interactions. The findings highlight the importance of visual communication in dolphin social behavior, suggesting these gestures foster cooperation and signify non-aggressive intentions among the species.