[cLeEOGPw]

Hi, I'm from Lithuania, where people are smiling (or not smiling) in the exact same way as described in the article. I can assure you that teeth has absolutely nothing to do with this. Same goes for your missing muscle theory, absolute nonsense. It seems like you think people are way more conscious about smiling than they really are. I could not care less about my tooth when "deciding" whether to smile or not. It's not very conscious decision after all.

[mrjj]

I just mention tooth like interesting side factor. Surely it's not the main reason, but may be a consequence supporting the reason. And surely there is no nations that, holding their smiles just because of their tooth not glowing in the dark.

Maybe you confused with the mentioning teeth by itself, but its normal for cultural anthropology to try taking physiology, language, healthcare e.t.c as a whole if it giving any clues.

Talking about conscious we should consider that it is one of the reflexes "tamed" by human. Reflexes have its own specific muscle tension/relaxing patterns. You can see reflexes in clean form when looking on babies. Than human learning some communication norms and codes just imitating what it see around. Than he can use trained gestures, sounds e.t.c unconsciously, just little cortex fire and we performing it. We can train to suppress reflexes this way.

Imagine, we have salute gesture like scratching a nose. The muscle tension and motional pattern will be a little different from the case we really have an itchy nose.

Or you have a cough or just imitating cough sound. It's easy to separate. But if you spent time training imitate cough naturally it will look and sound naturally.

So we can differ several cases: Human smiling but suppressing it. Human smiling or well trained or self-trained to smile "sincerely". Human imitating smile of request.

And i behold that Russians: imitate smile on request very rough and this mean deficient practice of imitation. have suppressed smile relatively as often as other ones. smile noticeable rarely.

So we really have rare-firing reflex. What the reason? This is separate and interesting question.

[cLeEOGPw]

What do you mean "on request"? Because if someone asked me to fake a smile I would not even try to look sincere either. Deficient practice in imitation can be considered when a person actually wants to look like he's smiling sincerely, but for us it is the opposite. And we don't "suppress" smile - we do not feel any need to smile for random strangers. Unless you want to look offensive. Especially fake smile. Fake smile is mostly used by people who want something from you and are willing to be very annoying about it - usually want something bad to sell or somehow screw you over. I have no idea why are you coming up with those ridiculous theories about reflexes when there are very good reasons not to smile and not to fake smile to random people, and to smile to friends.