Anyone who has had a pet dog or a cat knows that the expressions on their faces may convey an emotion, such as anger or pleasure. For example, when a dog makes the familiar “puppy dog eyes ...

An expert vet explains the evolutionary reason for those puppy dog eyes, and it's probably not what you think.

The mournful eyes, the lingering stares, the sad sighs. Many pet parents leave the house each day with a dog or cat watching somberly from the window. Social scientists have found that pet owners ...