Can Dogs Sense Emotion?
Your dog may know what that smile on your face means.
Check Out This Month's Most Popular Topic
Key Facts In This Video
Emotions expressed through the face aren't symmetrical. (0:21)
When dogs look at pictures of other dogs or random objects, they look either left or right, but tend to look more in one direction at human faces. (1:43)
Researchers have yet to find another animal with this trait. (2:34)