We humans smile a great deal.  We smile when we’re happy; we smile when we’re sad, to disguise the feeling from others or perhaps to try to cheer ourselves up.  We smile when we’re angry for similar reasons of disguise, and we smile sometimes, especially in America, to show off our expensive teeth.

We smile when we’re told to get ready for our picture to be taken, which is almost endlessly in this era of smart phones and social media.  Smiling makes us look happier, more confident, warmer, more beautiful, and about two years older.

Wait, what?

Yep.  The research shows that smiling makes people rate you as about two years older than if you don’t smile.  How can this be?  We are all convinced that smiling makes us look younger.  But it turns out that the wrinkles that form around your eyes when you smile cause viewers to rate you as older than you are, or would be if you kept your mouth in a straight line.

In a culture that worships youth, this finding is a serious blow to our established protocols.  What do we do?  Smile to look good, or maintain a neutral expression to look younger?  Which will you do now that you know?

I’m old enough that adding two years to my age is merely gilding the lily, so I can go either way, depending on whether I want to look more confident and warmer, or younger.  But here’s a suggestion for those of you who still want to have your facial expressions both ways.  Try the so-called Mona Lisa smile – an enigmatic upturn at the sides of your mouth, not enough to create those wrinkles, but enough to let the viewer know you are serene.

There’s another trick, which is to look surprised by opening your eyes wide and raising your eyebrows.  That makes you look younger, apparently – no wrinkles – and makes your face as almost as interesting as a smiling one.

More seriously, human interaction begins with the face – in the cradle.  That’s why we care so much about getting our facial expressions mastered.  It’s the aspect of our fellow human beings we study the most because it’s where we get the most important emotional cues and signals about what the other person is intending. As infants, we start studying our mamas’ and papas’ faces for cues about life, food, and happiness.  We basically never stop studying faces for the rest of our lives.  (Including our own, as teenagers.)  Of course, most of the knowledge we develop is unconscious. If you want to consciously master body language, you need to start with the face.

And what stories faces tell.  Starting from the top, those wrinkles in the forehead are a sign of engagement with the world, because we raise our eyebrows to show interest.  Wide open eyes carry a similar message.  By the time we get to the smile – or frown – we already can intuit a good deal about the person in question, whether we’re meeting them for the first time, or we know them well already.

My grandmother used to say that when you are young, you have the face you are born with.  By the time you are a grownup, you have the face you deserve.  That sounded harsh to me as a child, but now that I’m almost as old as my grandmother, I understand her comment a little better.  Our habitual expressions are the manifestations of our habitual thoughts, and by the time we’ve been on this planet for four decades or so, our face tells the world a good deal about our habitual thoughts.

The next time someone wants to take your picture, will you smile or look surprised or stay neutral?  Up to you, but now at least you know what’s at stake.