A smile is a smile or is it-?

A smile is a smile

When a wolf shows his teeth,.,./,./.,.,

.,.,.,…,.He means business

When we humans show our teeth it’s called a smile

Is the difference an evolutionary thing and once upon a time we smiled for the same reason wolves smile today-?

is a smile universal-? Just asking (:-

Dada smile:

http://tinyurl.com/kpsv7cj

Now this IS a smile—

http://tinyurl.com/p2pzhs3

What are you smiling about-?

Your earlier thread here had an identical OP. It’s still not suitable for General Questions.

Moderator Action

This post is identical to the OP of this thread, which was moved to MPSIMS: http://boards.straightdope.com/sdmb/showthread.php?t=763426

Since this is not a factual question, this copy is closed.