The cutest of all? When we offer up a big, goofy grin, she matches us with a smile of her own. But are our dogs really "smiling" the way humans do? We asked a veterinarian about what our canine ...

She added, "I cannot smile anymore," and demonstrated on camera saying, "Look, this is as big as I can smile." Trainor’s brother, Ryan, admitted he teased her a bit about her inability to smile ...

You’ve probably heard the claim that it takes more muscles to frown than to smile. It’s usually framed as a feel-good reason to turn your frown upside down – less effort, more joy.

If humanoid robots make you a bit queasy — would it help if they had fleshy faces that can smile at you? The uncanny feat is the result of new technology using engineered living skin tissue and ...

NPR's Ayesha Rascoe speaks to Sebastian Korb, a senior lecturer in psychology at the University of Essex, about a new study showing that even forcing a smile can improve a person's mood.