Smiles Hide Many Messages—Some Unfriendly
Smile while your heart is breaking, put on a happy face, say cheese. We’re so used to smiling on demand that to do otherwise can seem antisocial. Even going through the motions of a smile, scientists have found, can make us feel happy.
But smiles take many forms, and not all of them sound a single, upbeat note. According to recent research, smiles are more like Morse code, silently broadcasting distinct, nuanced messages. A smile might be signaling “Do that again” (reward), “I want to get along with you” (affiliation) or “I’m No. 1 around here” (dominance). Most of us receive these nonverbal signals loud and clear; they register in the chemical cocktail infusing our saliva and the thrum of our heartbeat, says a study published last month in the journal Scientific Reports.
“Different smiles have different impacts on people’s bodies,” said Jared D. Martin, a doctoral student who led the study in the lab of University of Wisconsin psychology professor Paula Niedenthal, working in collaboration with Eva Gilboa-Schechtman of Israel’s Bar-Ilan University. Along with poker players, psychologists have long known that our facial expressions can betray our emotions. But no one has demonstrated exactly how this works, Mr. Martin said.
To explore whether certain types of smiles provoke distinct physiological responses, Mr. Martin’s team set up an experiment based on public speaking. Research shows that most people would rather get zapped with an electric shock than give a five-minute speech about themselves. It’s a handy way to examine how our bodies register stress. So in this experiment, 90 healthy male undergraduate students delivered three spontaneous speeches about themselves, each to an audience of one. The listener smiled away on Skype while they were talking.