From the point of view of science, everything is simple. In our body there is no “single hair management center”;Each area of the skin on which hair grows independently is responsible for its color, length, growth rate and texture.
Hair color depends on how much melanin is producing follicles, and what melanin it is. It can be two types: one color in hair in black (or, depending on the concentration, in the shades of the light), the other in the red (or, in less concentrations, makes people blondes). The production of the pigment depends on many factors and is constantly changing: the blondes with age increase the production of dark pigment and become darker, with the loss of the ability to produce both pigment, the hair becomes gray.
Different parts of the body are covered with follicles of different nature: some are active from birth, others need a strong increase in the amount of hormones in the blood to earn money. The production of melanin in them is also regulated in different ways, therefore, on the body of an adult can be up to five different types of hair, the color of which does not depend on each other. Most of the dark variety of melanin, as a rule, is producing eyebrow follicles.
The maximum hair length and its growth rate also changes arbitrarily from the site to the site.