Sure, it's more or less a given that we smile when we're happy and we smile when our picture is taken. But do we also smile automatically throughout the day when we make eye contact with strangers? How often do we smile in conversation?
For centuries, artists and writers taken on contemptuous smiles, regretful smiles, sad smiles, and angry smiles. But science is finally catching up and accepting that the smiling is not a straightforward expression of happiness.
Charles Darwin was the first scientist to examine the smile. He wrote about it in The Expression of the Emotions in Man and Animals in 1872.
"In truth, [Darwin] threw up his hands and said that he didn't quite know what the smile was about," said Marianne LaFrance, a professor of psychology at Yale University, in an interview on the State of Things.
Concurrently to Darwin, a French physiologist named Jean-Marc Duchenne was conducting experiments on smiles by sticking electrodes into his patients' faces. He came up with the Duchenne smile, a distinction that still stands as a genuine smile.
"[Duchenne] began the notion that different muscles reflected different smiles, and different smiles came from different psychological and emotional states," said LaFrance.
But do smiles conceal emotion as much as they convey emotions?
"Most of the smiles that you see in the course of a day, most of the smiles that you both see and emit and others see, are not quote 'genuine' smiles. That does not mean that we're all fakes. Well, actually it may. But what it does indicate is that there are two brain systems involved in smiling, an intentional system and an automatic system," said LaFrance.
LaFrance is the author of “Why Smile? The Science Behind Facial Expressions.” Her research suggests that on average, women smile more frequently than men and the durations of the smiles last longer. But this does not mean that women are necessarily happier than men. Gender roles and social expectations act on women's smiles. But as gender roles change, do smiles also change?
"I was interested to read in [LaFrance's] book that stay-at-home fathers smiled as much as stay-at-home mothers. So the role of caretaking involves smiling. And as gender roles are changing, I imagine that these gender expectations are changing along with them. Gender expectations are no more static than gender is," said Priscilla Wald, a professor of English and Women’s Studies at Duke University.
While LaFrance's writing explores how smiles vary along the lines of gender and culture, she also examines occupation.
How does work and professionalism change smiles? Dave McKenna is a writer based in Washington D.C who focuses on professional sports. He recently penned the Slate article “The End of Joy: Why Do Athletes Look So Angry When They Do Something Great?”
McKenna writes about LeBron James' winning basket during Game One of the Eastern Conference Finals. James' got the ball with one and a half seconds left, and he decides to bolt to the basket.
"Here's this huge guy [LeBron James. He had all the athletic gifts to do this--to get from the top of the key, surprise everyone, run to the basket, make this incredible lay-up. It was amazing. Everything came together. It won the game... And at this amazing moment, he just scowled," said McKenna.
McKenna documents the disappearing smile in various professional sports, including basketball, baseball, and football.
"Tim Tebow, the devoutest player out there, you'd think he'd have some joy, the joyful spirit. When he scores, the points towards the Heavens with this rage. Like God didn't pay the rent this month," said McKenna.
LaFrance suggests that this trend scowling at pro-sports games is a pose that athletes adopt to display their seriousness about the game.
"My sense is that it's not rage. It's a matter of 'I am about business here. I am really good at what I do. And what I do is professional. It has nothing to do with fun,'" said LaFrance.