Humans can produce thousands of distinct facial expressions – including 19 different types of smile, according to research by the American psychologist Paul Ekman. However, only one of these is ...

Doctors may soon be able to diagnose a severe form of depression simply by looking at someone's face. This type of depression, called melancholia, is marked by a complete loss of interest in daily ...

If a mouse is in a lot of pain, an experienced handler may see it in the animal’s facial expression—its narrowed eyes and bulging cheeks. But, subtler facial expressions may be more difficult to match ...