a coworker added me to facebook over the weekend and said to me yesterday "i was looking through your pictures and i have never seen someone smile as much as you do!"

i do genuinely smile a LOT and i also feel like i will get crows feet and laugh lines early but i will also know they are worth it!

It's easy to tell when a smile is genuine. Your face moves in a slightly different way than if you're just showing your teeth and pretending to grin.

It's in the eyes.. your eyes sparkle when you smile- atleast they do in my head haha

I love "real" smiles! They just light up the face!

It's all about the crinkly-eyes (crows feet), definitely.

I knew I would be wrong, but the one on the left looks more genuine to me.

I thought it was easy. The eyes give it away.

the vein popping out of her forehead was a dead giveaway.

Julia Roberts is the fake smile queen. The one on the right is fake. Don't care what the 'experts' say.

I agree Samantha & Jinx - I chose the left because it doesn't look forced.

Exactly what I thought, less forced.

Even though I do not care for Ms. Roberts as an actress I objectively looked at the two photos. The first photo made me feel cold while the second photo actually made me feel warm and good and smile in return.

It wasn't here mouth that I was responding to it was her eyes. There's a distinct difference in her eyes in both photos. In the second photo she's smiling with her eyes, there's warmth and she's connecting with someone off camera. First photo there's nothing in the eyes except blankness and coldness.

I;d like to thank Malcolm Gladwell's Blink for helping me read people's face better than I could before. Come's in handy all the time.

She's gorgeous either way..

Got it, it's all about the eyes

Tyra taught me that you better smile with your eyes.

How did I forget that, Geek?!

I disagree,
because the first picture is just less exaggerated (as lies usually are) and the eyes are more thoughtful. The second picture displays glazed over eyes and a more anxious, extreme intention.
They are obviously both 'genuine or real' smiles, but the first one is sincere.

2nd duh.

I totally misread the question. I thought it was asking which one was fake. I am too tired!

If you know anything at all about Julia ROberts you know that she always has a BIG smile on her face...unlike the fake smile on the left!! She has such a beautiful smile!!

That was easy.You could tell the second one was a real smile.She always has the big smile.(which I like)

Don't worry about crow's feet because you smiled a lot. It's worth it

And we always have eye cream tho. LOL.

I don't know if I can really judge from these pictures. She looks genuine in both. In the second one she looks as though she finds something really funny and in the first one it looks as though she's just beginning to break into a bigger smile... Though, I do agree that the eyes say it all.

What is "fake"? They both look real to me but I thought fake means that the smile does not reflect the internal state of the subject.

I think they're both genuine. The first one looks like she is looking at something she loves like a child showing compassion or a child bringing a mother a flower. The second one looks like she just made eye contact with David Letterman. She can't seem to stop laughing or flirting whenever she is around him.