Dimples are formed by muscle activity under the skin. Most muscles of human body are firmly attached to bones through tendon fibers, such as pectoral muscles and lower limb muscles. Facial expression muscles are an exception. It is directly attached to the facial skin. When the expression muscles contract, it will affect the facial skin, so various wrinkles appear on the face, resulting in expressions of joy, anger, sadness and joy. The two dimples on the smiling face are formed by the relative influence of facial skin and facial expression muscles such as buccal muscle and smiling muscle.

Whether there are dimples is related to the development of expression muscles. People with less plump smiling muscles and less subcutaneous fat on their faces generally have no dimples when they smile. In fact, you can also make dimples the day after surgery.

dominant inheritance

Dominant inheritance means that as long as there is one dominant gene in a pair of genes, certain traits will not be displayed in pairs, such as sharp eyes and double eyelids. In fact, it can also be made by surgery the day after tomorrow.

The most common traits controlled by 10 are: earlobe and earlobe-free; Roll your tongue but not roll it; Hairline has beauty tip and no beauty tip; Thumb can bend to the back, not to the back; The index finger is longer than the ring finger and shorter than the ring finger; When the left and right hands are embedded, the right thumb is on the top and the left thumb is on the top; Double eyelids and single eyelids; With dimples and without dimples; Normal feet and flat feet; Normal color vision and color blindness; Albino and normal skin.