People who study the physiology of facial expressions agree, thanks to the research of pioneering 19th-century French physician Guillaume Duchenne, that it's easy to recognize a genuine smile, as opposed to one that's merely social.
Looking at the two photos of smiley Julia Roberts up there, can you guess which one fits the criteria for a genuine smile? I'll explain it after you answer.
Can You Guess Which Julia Roberts Smile Is Genuine?
Can you guess which Julia Roberts smile is genuine?