It's very well said that world smiles with you. We all experience that smiling (irrespective of a genuine or fake smile) faces are more liked that neutral, sad ,or angry faces because smiling makes us feel better. Smiling secretes a hormone called as Endorphin inside brain that generates happy feelings and also reduces level of stress hormone Cortisol and Epinephrine (secretion from Adrenaline gland). Hence smiling at each other generates a positive feedback loop.
|Smile enhances your face value.|
|Japanese are trained to smile like westerns.|
This theory applies for smiling too and we widely witness it. More you smile at people in appropriate situations; more often you would get similar feedback from them. If you cannot portray a genuine smile, start smiling politely (in other words - fake smiling). Feedback from others in form of smiles, easiness, interest, or comfort displays would lead to positive feelings in your mind. Falling into a loop of initiation and feedback, your mental state starts to change. Sooner or later, you would start to portray a genuine smile unconsciously.
It’s an innate survival mechanism we all have that allows us to connect with each at deeper psychological levels and feel our existence (more meaningful) by seeking feedback from others. We can find trails of feedback principle in many practical and conceptual factors in daily life.
Facial feedback to smile is natural and widely used in commercials. It's not surprise that we find faces in various entities around us or also draw faces on own.