Narrator: This is Science Today. We all know the feeling. The conversation lulls, leaving a heavy, uncomfortable silence. You flash a smile across the table and get a nervous grin in response. But what do those upturned corners really mean? Doctor Paul Ekman, a psychology professor at the University of California San Francisco says they are one of several "deceptive" smiles that humans constantly deploy.
Ekman: The false smile is made to deliberately mislead another person to make them think that you're enjoying yourself when in fact your not.
Narrator: Ekman says deceptive smiles are used to hide our true feelings, and are difficult to distinguish from genuine smiles of enjoyment.
Ekman: Most of us are really not able to tell whether someone is lying to us or not, even if it's a very serious lie, and I believe most of don't really want to know anyhow. And besides which, who wants to go through life being suspicious all of the time about whether someone is misleading us?Narrator: For Science Today, I'm Larissa Branin.