100 YEARS OLD AND STILL TRYING TO KEEP SMILING...

HELLO! And thank you so much for dropping in. I would greet you with a smile, but I am no longer sure that I know how. I have been reading a paper entitled “Dynamic properties of successful smiles” that has just been published in the journal Plos One, and it has gone so deeply into the matter of smiling that I can no longer feel sure about how to do it properly.

The Oxford English Dictionary, I just discovered, includes 16 verbs that can mean ‘to smile’. One may arride or subride, besmile, outsmile or resmile, simper, sneer or fleer (which is to smile flatteringly or fawningly). One may smicker, smirk, smirtle or smirkle which may well turn out to be the same thing, though there could also be a subtle difference between them. As for smilesmirk, well all I can say is that I think that is overdoing it.

Back on the Plos One paper, it gives the results of research at the University of Portsmouth into people’s assessments of smiles created by manipulating digital images. Subjects were shown 27 moving images of the same face with different smiles.

The angle, breadth and degree to which the teeth are showing were all changed from picture to picture and the subjects were asked to assess the smile on a number of scales. These included the genuineness of the smile, the emotions it expressed, its pleasantness or creepiness and its overall effectiveness.

Analysis of the results, however, showed that smiling is a far more complex matter that had previously been thought. Big smiles are not necessarily better received than small smiles, and the question of whether one should bare one’s teeth when smiling is very unclear.

“We found that a successful smile involves an intricate balance of mouth angle, smile extent and dental show in combination with dynamic temporal timing,” they say. The ‘dynamic temporal timing’, incidentally, involved creating an asymmetry in timing between the motions of the left and right sides of the mouth during the formation of the smile.

They found no significant differences between male and female assessments of smiles, nor any relation between assessments and the amount the subjects had drunk that day (though they did exclude from the experiment subjects who had consumed six or more alcoholic drinks that day.

“Successful smiles,” they say “have mouth angles of about 13-17 degrees and smile extents of about 55-62% the interpupillary distance.” (That’s the distance between the eyes.) “…the best smiles represent a diverse collection of different combinations of facial parameters. There is not a single path to a successful smile.”

I hope all of the above explains why I did not greet you with a smile when you began to read this piece. Trying to assess the angle of my smile, its extent compared with my interpupillary distance, how much of my teeth to show and whether the left side of my smile should move before or after the right side is enough to drive the smile off anyone’s face. Keep smiling anyway.