Does smiling make you happy? Smiling doesn't seem like a particularly complicated act: You feel a happy emotion, the corners of your mouth turn up, your cheeks lift and your eyes crinkle. The overall effect tells the outside world that you're feeling happy on the inside. It's simple and, in most cases, totally spontaneous. We typically smile without making a concerted effort to do so. In fact, most people are turned off by the appearance of a smile that takes effort, because so often it's obvious it's fake. It's not hard to detect a fake smile -- it usually involves only the mouth, not the eyes. The appearance of a genuine smile, one involving specific changes in the eyes in addition to the mouth (notably a crinkling of "crow's feet" and a downturn of the outer points of the eyes) is called a Duchenne smile, after the neurologist Guillaume Duchenne. Back in 1862 he identified the facial muscles involved in spontaneous smiling