When a baby smiles at you, it's almost impossible not to smile back. This spontaneous reaction to a facial expression is part ...

Facial mimicry refers to automatic copying of another person’s facial expressions. When one person smiles, a listener may ...

Whether at a birthday party in Brazil, a funeral in Kenya, or protests in Hong Kong, humans all use variations of the same facial expressions in similar social contexts, such as smiles, frowns, ...