In all honesty... I think smiling is a form of insecurity.

[RPJesus]

Some people have naturally frowny or smiley faces.
I'm just horrible, apparently, because I always look so pissed (but that's just my huge eyebrow head crushing the rest of my face). Really, sometimes I look like I'm frowning. People say 'what's wrong?' and I don't get it. My dad always looks pissed, whether he is or not.
And some people always look a bit like they're smiling. Like Ville Valo... though, that might just be because he's drunk.

So maybe it can depend on the person.

[Laugh at face of Danger]

It comes form a doctor (pyramid of dots ) therefore i must take the counter side.

I smile because i'm happy, because words don't explain what i feel

[Alive-Cat]

As a kid I never smiled unless someone gave me a reason to. I can honestly say that if I totally relaxed my jaw and mouth, it would go into a slightly downward curled straight line. Not as frowny as a frown, though.
But yep, for about the past 6 months I've been smiling all the time, it's pretty cool. And yeah, I guess it is an insecurity, for me, anyway. I DO want people to know I'm happy.

[escobert]

I must be a very insecure person! I thought I was happy

[Lionx]

Because i am too lazy to frown.

[Mum]

Smiling is infectious,
you catch it like the flu,
When someone smiled at me today,
I started smiling too.

I passed around the corner
and someone saw my grin
When he smiled I realized
I'd passed it on to him .

I thought about that smile
then I realized its worth,
A single smile, just like mine
could travel round the earth.

So, if you feel a smile begin,
don't leave it undetected
Let's start an epidemic quick,
and get the world infected!

[G SpOtZ]

Oh no, someone may assume what I'm feeling. Quick, smile!

Your chin, lower lip, and upper lip are most comfortable in a smiling-like position.

My upper lip is most comfortable on your lower lip, sugarbuns.

That made me smile.

[Anaisa]

Smiling is infectious,
you catch it like the flu,
When someone smiled at me today,
I started smiling too.

I passed around the corner
and someone saw my grin
When he smiled I realized
I'd passed it on to him .

I thought about that smile
then I realized its worth,
A single smile, just like mine
could travel round the earth.

So, if you feel a smile begin,
don't leave it undetected
Let's start an epidemic quick,
and get the world infected!

Good idea. That way when they've all got big smile lines, they can come to my beauty salon to get botoxed, an I'll be a rich lady.

[-N-]

BoB's mum!

[Vincent, Thunder God]

People feel compelled to make sure people know what they're feeling, so they smile rather than just take the risk of letting others assume what they're feeling.

I disagree. Smiling is a reflex that most people have when something occurs to make them happy or laugh. Occasionally people will try to do a fake smile, and in that case they may well be insecure of something. But you can't just generalize on much-used social reflex.