Smile, you're being analyzed.

[Eliza Hodgkins 1812]

Originally Posted by innerSpaceman

Yep, there was a bit about this in Time a couple of weeks ago. Not comparing Brit and American smiles, but comparing fake and genuine smiles. Turns out it's all the eyes and not at all in the mouths.

That's not surprising. Crow's feet are a good indicator of people who have spent a lot of their days either happy or easily amused.

It's strange, but when I'm truly happy and either looking wide-eyed at something, or smiling/laughing, I almost have a happy, tingly sensation in my eyes. Like, my eyes are experiencing a feeling that's not unlike what my heart feels like when I feel a sudden rush of love.

Strange but true.