Smiling is the second most contagious facial expression, coming in second only to yawning. Unfortunately, some people can’t smile or yawn freely – they cover their mouths, turn away, or keep their lips shut in public. In many cases people…
Smiling is the second most contagious facial expression, coming in second only to yawning. Unfortunately, some people can’t smile or yawn freely – they cover their mouths, turn away, or keep their lips shut in public. In many cases people…