Biochemistry of smiling and frowning Let’s say you experience a positive situation and you see a friend you haven’t met in a long time. This means that neuronal signals travel from the cortex of your brain to the brainstem (the oldest part of our brains). From there, the cranial muscle carries the signal further towards the smiling muscles in your face. Sounds simple enough right? And yet, that’s only where it starts. Once the smiling muscles in our face contract, there is a positive feedback loop that now goes back to the brain and reinforces our feeling of joy. To put more succinctly: Smiling then, seems to give us the same happiness that exercising induces terms of how our brain responds. In short: our brain feels good and tells us to smile, we smile and tell our brain it feels good and so forth. That’s why in a recent research scientists concluded “that smiling can be as stimulating as receiving up to 16,000 Pounds Sterling in cash.”
A frown (also known as a scowl) is a facial expression in which the eyebrows are brought together, and the forehead is wrinkled, usually indicating displeasure , sadness or worry , or less often confusion or concentration. The appearance of a frown varies by culture. Although most technical definitions define it as a wrinkling of the brow, in North America it is primarily thought of as an expression of the mouth. In those cases when used iconically, as with an emoticon, it is entirely presented by the curve of the lips forming a down-open curve. The mouth expression is also commonly referred to in the colloquial English phrase "turn that frown upside down" which indicates changing from sad to happy.