Is she or is she not smiling, is it her secret weapon?

Most women shudder at the thought of leaving the house without a carefully applied layer of foundation, lipstick, and mascara. Spending hours in front of the mirror and splashing on expensive cosmetics, as it turns out, however, could all be a waste of time. According to research, wearing makeup does little to boost a woman’s attractiveness. In fact, scientists say that the trick to appearing more attractive to others have more to do with a person’s facial expressions and natural looks—particularly their smile. If they have dimples they look youthful for many years into the future.

Studies show that people think they already know someone if that person smiles at them,from behind a mask, even if it's an absolute stranger. The theory: Scientists believe the need to bond is rooted in our evolutionary past. Survival was more likely when people combined forces, so humans acquired the smile as a way to signal friendliness and to induce an agreeable sense of shared history, whether there was one or not. Today, when someone smiles, a glum mood is lifted, an apology is accepted, a person's shaky self-confidence gets a boost, a deal is struck, a physical attraction is communicated. But change the cast of a smile and the consequences shift. A rival grins to get under your skin; a bully smirks to unsettle his mark. Understanding the nuances helps ensure that you send—and receive—the right mouth message. Here, some intriguing insights about this familiar gesture. Outer Smile, Inner Darkness Ironically, a smile can express contempt. Bullies—whether they're on the playground or in the office—may want the recipients to see their glee and realize their malevolent intent. The result is a conscious disconnect between outward expression and inner feelings. Other times, the disconnect may be unconscious, the result of pushing aside negative feelings. A person may have heard as a child that enraged feelings should never be expressed, so even the slightest inkling of anger is covered with a smile. The Most Powerful Expression Even a fleeting smile has the capacity to burrow deep into the subconscious of the person who sees it and set off positive changes from within. For example, a smile of just a mere four-hundredths of a second (what researchers refer to as subliminal priming) is enough to produce a mini emotional high in others; it makes people see things around them in a more positive light. Boring material becomes more interesting, or a nondescript picture seems to have more flair. Indeed, researchers have found that some foods even taste better when preceded by a subliminal smile. And what's more, these expressions are contagious: In one study, when participants were exposed to these smiles—even though they couldn't remember seeing them—their own faces mirrored what they "saw."