What really distinguishes a fake smile from the genuine article? And why do people give fake smiles, anyway? Science offers some answers.
We’ve all seen fake smiles — in school pictures, on the faces of clerks taking orders at Starbucks, from politicians, and in countless other scenarios. It turns out that people are better at detecting fake smiles in photos than in real life, because we tend to study photos more closely. And the key indicator of fakiness is not the position of the grinning mouth and bared teeth, but the eyes. A muscle around the eye called obicularis occuli contracts when a real smile flashes across the face, giving the eyes that crinkle that separates the real deal smile from the pretenders. Most people who aren’t actors, con men, or psychopaths just can’t control that muscle.
Studies also indicate that women smile more than men. The theory is that girls are encouraged from an early age to be more expressive emotionally than boys. Girls also learn faster than boys that a good fake smile can be an appropriate, polite, social response under certain circumstances — like when Gramma gives you a lame gift for your birthday. In view of that, it also should not be surprising that women tend to be more adept than clueless male brutes at detecting fake smiles in others and accurately determining what a person’s smile really means.
It follows that if people learn to give fake smiles, and then realize that people often can’t tell the difference, they may decide to wear a fake smile as a matter of course. When you walk down a Midwestern street and see people with smiles on their faces, how many of them are fake? No way to tell for sure, of course — but studies also show that people smile much more infrequently when they are alone.